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Technical sulfur. Specifications
Sulfur
– element of the periodic system of chemical elements D.I. Mendeleev, with atomic numbers 16. Denoted by the symbol S (from the Latin Sulfur). In hydrogen and oxygen compounds it is found in various ions and forms many salts and acids.
Sulfur is the sixteenth most abundant chemical element on Earth. It is found in a free (native) state, and in the form of compounds.
Sulfur, along with oil, coal, table salt and limestone, is one of the five main types of raw materials of the chemical industry and is of strategic importance for providing the population with food, since in addition to nitrogen, phosphorus, potassium, calcium and magnesium, it is a necessary mineral nutrient for plants, a source soil fertility and increased productivity.
In general, the global sulfur industry can be divided into two sectors based on the forms of sulfur production: specialized and “by-product”. The specialized sector focuses exclusively on the extraction of sulfur or pyrites from deposits of these raw materials. This sector accounts for about 10.5% of the total global sulfur production.
Production:
Modern methods of industrial sulfur production can be reduced to three types:
– Extraction of native sulfur (10.5%);
– Production of industrial and natural gases from hydrogen sulfide;
– Obtained from sulfur dioxide released in the process of metallurgical production. The extraction of sulfur from hydrogen sulfide contained in oil and natural gas fields has, first of all, an environmental goal, since the utilization of sulfur or the neutralization of its compounds is mandatory when obtaining the main hydrocarbon products. Thus, in the process of refining oil, natural gas, as well as coke production, sulfur is a by-product.
| It is necessary to note the exceptional diversity of commercial forms of sulfur. Such a wide range reflects the different origins of sulfur (natural, associated, etc.), features of isolation or purification technology, and areas of application. Currently, the main ones are lump, granular and liquid | The advantages of lump sulfur are the simplicity of the preparation technology, which consists of pouring and solidifying liquid sulfur on a concrete site, followed by breaking up sulfur blocks up to 3 m high, stacking them and loading them onto vehicles. The main disadvantage is losses of up to 3% during the operation of excavator loosening of sulfur blocks |
| Granular | Granulated sulfur is called sulfur, consisting of homogeneous particles with a diameter of 1 to 5 millimeters. The presence of particles less than the specified size and sulfur dust is unacceptable. Granulated sulfur is convenient for the consumer and transportation, practically does not generate dust during loading and unloading operations, which improves sanitary and hygienic working conditions and production culture. |
| Scaled | Sulfur flakes 0.5-2 mm thick, formed when solidified sulfur is cut off from the surface of a crystallizer drum, partially immersed in a liquid medium and rotating at a certain speed |
| Liquid | Liquid sulfur as a primary form is in growing demand. This is especially true for large-capacity consumers and transportation over relatively short distances (up to 800-1000 km), when energy costs for maintaining sulfur in a molten state are less than when melting it at the point of use. Capital investments and energy costs associated with storage, transportation, and unloading of liquid sulfur are compensated by the high purity of the product, the impossibility of its contamination, the absence of losses and high production standards. |
Application:
Sulfur is used throughout chemical production. Sulfur is necessary for the production of sulfuric acid, dyes, sulfites, in pulp and paper, textile and other industries.
According to various sources, approximately half of sulfur use is for the production of sulfuric acid.
Approximately 20-25% of sulfur and technical sulfur is spent on the production of various sulfites.
About 10-15% is for agricultural needs as raw materials for the production of pesticides to protect plants from harmful insects.
Also, 10% of sulfur is used in the rubber vulcanization process.
Sulfur is also used in the areas of artificial fibers, phosphors, pigments, dyes, in the production of matches, explosives, and dosage forms.
Recently, in North America and Europe, sulfur has found exotic use as an additive or replacement for bitumen, for four main reasons:
– The first reason is the possibility of reducing the consumption of bitumen, the price of which has increased significantly due to rising oil prices and the energy crisis. And reducing the bitumen content in sulfur bitumen binders due to the addition of cheaper and available in significant quantities of sulfur makes it possible to reduce the cost of constructing a road surface;
– The second reason is the significant depletion of available reserves of non-metallic materials used in the construction of road surface layers, which have to be imported from other, usually remote, areas. The use of sulfur bitumen binders allows the widespread use of local sandy soils, weak stone materials, ash and slag in road construction, which also provides a significant economic effect.
– The third reason is the significant improvement in the properties of asphalt concrete mixtures based on sulfur bitumen binder. These include higher compressive strength, which makes it possible to reduce the thickness of the corresponding layers of road surfaces; higher thermal stability without a significant increase in rigidity at low temperatures, which reduces the risk of cracks forming in the layers of road pavements in cold (winter) times and plastic deformations in hot (summer) periods.
– Possibility of preparing mixtures based on sulfur bitumen binder at lower heating temperatures of the components; higher resistance of sulfur bitumen materials to dynamic loads; higher resistance to gasoline, diesel fuel and other organic solvents, which makes it possible to use them in coatings in parking lots and service stations.
– The conclusions are based on twenty years of experience in the use of sulfur in road construction in the USA, Canada and Western Europe.
World sulfur production is 80,000,000 tons/year (first decade of the 21st century).
Ecology:
Sulfur compounds occupy one of the first places among pollutants in their negative impact on the environment. The main source of pollution with sulfur compounds is the combustion of coal and petroleum products. 96% of sulfur enters the Earth's atmosphere in the form of SO 2, the rest comes from sulfates, H 2 S, CS 2, COS, etc.
In the form of dust, elemental sulfur irritates the respiratory system and human mucous membranes, and can cause eczema and other disorders. The maximum permissible concentration of sulfur in air is 0.07 mg/m 3 (aerosol, hazard class 4). Many sulfur compounds are toxic.
This standard applies to natural technical sulfur obtained from native sulfur and polymetallic sulfide ores, and industrial gas sulfur obtained from the purification of natural and coke oven gases, as well as waste gases from oil and shale processing.
Technical sulfur is used for the production of sulfuric acid, carbon disulfide, dyes, in pulp and paper, textile and other industries and for export.
The requirements of this standard are mandatory.
GOST 127.1-93
INTERSTATE STANDARDS
TECHNICAL SULFUR
INTERSTATE COUNCIL
ON STANDARDIZATION, METROLOGY AND CERTIFICATION
Minsk
Preface
1 DEVELOPED by the Research and Design Institute of the Sulfur Industry with a pilot plant, Ukraine
INTRODUCED by the Technical Secretariat of the Interstate Council for Standardization, Metrology and Certification
2 ADOPTED by the Interstate Council for Standardization, Metrology and Certification on October 21, 1993 (by Order No. 1 to Protocol No. 4-93)
| Name of the national standardization body |
|
| Republic of Armenia | Armgosstandard |
| Republic of Belarus | Belstandart |
| The Republic of Kazakhstan | Gosstandart of the Republic of Kazakhstan |
| The Republic of Moldova | Moldovastandard |
| Russian Federation | Gosstandart of Russia |
| Turkmenistan | Turkmen State Inspectorate |
| The 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 March 21, 1996 No. 198, the interstate standard GOST 127.1-93 was put into effect directly as a state standard on January 1, 1997.
4 IN REPLACEGOST 127-76(in terms of sections , , , , )
INTERSTATE STANDARD
Date of introduction 1997-01-01
This standard applies to natural technical sulfur obtained from native sulfur and polymetallic sulfide ores, and industrial gas sulfur obtained by purification of natural and coke oven gases, as well as waste gases from oil and shale processing.
Technical sulfur is used for the production of sulfuric acid, carbon disulfide, dyes, in pulp and paper, textile and other industries and for export.
The requirements of this standard are mandatory.
1 TECHNICAL REQUIREMENTS
1.1 Technical sulfur must be produced in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner.
1.2 Technical sulfur is produced liquid and lump.
1.3 Technical sulfur codes according to OKP are given in .
1.4 According to physical and chemical indicators, technical sulfur must meet the standards specified in the table .
Table 1
| Norm |
|||||
| Grade 9998 | Grade 9995 | Grade 9990 | Grade 9950 | Grade 9920 |
|
| 1 Mass fraction of sulfur, %, not less | 99,98 | 99,95 | 99,90 | 99,50 | 99,20 |
| 2 Mass fraction of ash, %, no more | 0,02 | 0,03 | 0,05 | 0,2 | 0,4 |
| 3 Mass fraction of organic substances, %, no more | 0,01 | 0,03 | 0,06 | 0,25 | 0,5 |
| 4 Mass fraction of acids in terms of sulfuric acid, %, no more | 0,0015 | 0,003 | 0,004 | 0,01 | 0,02 |
| 5 Mass fraction of arsenic, %, no more | 0,0000 | 0,0000 | 0,000 | 0,000 | 0,03 |
| 0,000 | 0,000 | 0,000 | 0,000 | 0,04 |
|
| 7 Mass fraction of water, %, no more | 0,2 | 0,2 | 0,2 | 0,2 | 1,0 |
| 8 Mechanical contamination (paper, wood, sand, etc.) | Not allowed |
||||
Notes
1 Standards for indicators 1 - 6 are given in terms of dry matter;
2 The mass fraction of ash for liquid sulfur of grade 9998 should be no more than 0.008%, grades 9995 and 9990 no more than 0.01%;
3 The mass fraction of arsenic and selenium in natural sulfur obtained from native sulfur ores and in gas sulfur obtained from the purification of natural gases, as well as waste gases from oil refining, is not determined. In technical gas sulfur grade 9920, produced by coke-chemical enterprises, a mass fraction of arsenic of no more than 0.05% is allowed by agreement with the consumer;
4 The mass fraction of selenium in sulfur intended for the pulp and paper industry should be no more than 0.000%;
5 The mass fraction of water in liquid sulfur is not standardized. In lump sulfur, it is allowed to increase the mass fraction of water to 2% with the recalculation of the actual mass of the batch to the standardized humidity;
6 Lump sulfur intended for export should not contain pieces larger than 200 mm.
1.5 Indicators by points - tables are determined by the requirements of the consumer or regulatory organization.
1.6 An example of an order symbol:
Technical gas-liquid sulfur, grade 9998, GOST 127.1-93.
2 SAFETY REQUIREMENTS
2.1 Sulfur is flammable. Dust suspended in the air is a fire and explosion hazard. Lower concentration limit of flame propagation (ignition) - 17 g/m 3; auto-ignition temperature - 190° From toGOST 12.1.041.
Hydrogen sulfide released from liquid explodes at a volume concentration of 4.3 to 45%; auto-ignition temperature - 260° WITH.
2.2 Sulfur belongs to the 4th hazard class (GOST 12.1.005).
Sulfur causes inflammation of the mucous membranes of the eyes and upper respiratory tract, irritation of the skin, and diseases of the gastrointestinal tract; does not have cumulative properties.
Hydrogen sulfide is a poison that has a strong effect on the central nervous system.
Sulfur dioxide, which is formed when sulfur burns, causes irritation of the mucous membranes of the nose and upper respiratory tract.
Maximum permissible mass concentrations in the air of the working area: sulfur - 6 mg/m 3 ; sulfur dioxide - 10 mg/m 3 ; hydrogen sulfide - 10 mg/m3.
2.3 Production premises and laboratories in which work with technical sulfur is carried out must be equipped with supply and exhaust mechanical ventilation, ensuring compliance with the maximum permissible concentrations of harmful substances in the air of the working area.
Air control of the working area must be carried out in accordance with the requirements of GOST 12.1.005 using methods approved by the Ministry of Health.
2.4 All workers must be provided with special clothing and personal protective equipment in accordance withGOST 12.4.011.
3 ACCEPTANCE RULES
3.1 Sulfur is subjected to acceptance tests.
3.2 Sulfur is taken in batches. A batch is considered to be the amount of sulfur shipped to one address and accompanied by one quality document.
When transporting by water, each transport unit (barge, motor ship, tanker) is taken as a shipment of sulfur.
3.3 The quality document must contain the following data:
Name of the manufacturer and (or) its trademark;
Name and variety of product;
Batch number and date of shipment;
Numbers of railway cars or other vehicles (for direct deliveries);
Results of tests performed or confirmation of product compliance with the requirements of this standard;
Net weight;
Danger sign 4a and classification code 4133 according to GOST 19433;
UN serial number: for lump sulfur - 1350; for liquid - 2448;
Signature and stamp of the technical control department;
Designation of this standard.
3.4 To control the quality of lump and liquid sulfur, samples are taken from every fourth car (tank) of the controlled batch, but not less than from three cars (tanks).
When sending sulfur in a volume of less than three transport units, samples are taken from each transport unit.
When shipping sulfur by water, samples may be taken during loading (unloading) of barges.
4 TEST METHODS
4.1 Sampling and preparation of samples is carried out according to GOST 127.3.
4.2 Tests are carried out according to GOST 127.2.
4.3 The presence of mechanical contamination is determined visually.
5 TRANSPORTATION AND STORAGE
5.1 Lump sulfur is transported in bulk in gondola cars with bottom hatches, as well as by road and water transport. By agreement with the consumer, it is possible to transport sulfur in covered wagons. Car doors must be closed with safety shields.
Loading of gray contaminated vehicles is not allowed.
Liquid sulfur is transported in special heated railway tanks, used only for the transportation of liquid sulfur. Transportation is carried out in accordance with the instructions for the operation and maintenance of railway tanks.
5.2 Transportation of sulfur intended for export is carried out in accordance with the requirements of this standard or contract.
5.3 Lump sulfur is stored under a canopy or in open areas.
To avoid sulfur contamination, sites must be provided with industrial and storm drainage.
Liquid sulfur is stored in special insulated containers equipped with heating devices and pumping devices, as well as measuring instruments and exhaust pipes.
The containers must be marked “LIQUID SULFUR”.
6 MANUFACTURER'S WARRANTY
The manufacturer guarantees that technical sulfur meets the requirements of this standard subject to the conditions of transportation and storage.
The guaranteed shelf life of technical sulfur is one year from the date of shipment.
APPLICATION
(informative)
OKP codes for technical sulfur
| OKP code | CC |
|
| Technical natural sulfur | 21 1221 | |
| Technical natural lump sulfur | 21 1221 0100 | |
| grade 9995 | 21 1221 0110 | |
| grade 9990 | 21 1221 0120 | |
| grade 9950 | 21 1221 0130 | |
| grade 9920 | 21 1221 0140 | |
| Technical natural liquid sulfur | 21 1221 1000 | |
| grade 9995 | 21 1221 1010 | |
| grade 9990 | 21 1221 1020 | |
| Technical gas sulfur | 21 1222 | |
| Technical gas sulfur lump | 21 1222 0100 | |
| grade 9998 | 21 1222 0110 | |
| grade 9995 | 21 1222 0120 | |
| grade 9990 | 21 1222 0130 | |
| grade 9950 | 21 1222 0140 | |
| grade 9920 | 21 1222 0150 | |
| Technical gas liquid sulfur | 21 1222 1000 | |
| grade 9998 | 21 1222 1010 | |
| grade 9995 | 21 1222 1020 | |
| grade 9990 | 21 1222 1030 |
INFORMATION DATA
REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS
Sulfur is a substance that is located in the periodic table in group 16, under the third period and has an atomic number of 16. It can be found both in native and bound form. Sulfur is designated by the letter S. The known formula for sulfur is (Ne)3s23p4. Sulfur as an element is part of many proteins.
If we talk about the structure of the atom of the element sulfur, then in its outer orbit there are electrons, the valence number of which reaches six.
This explains the element's property of being maximally hexavalent in most combinations. There are four isotopes in the structure of a natural chemical element, and these are 32S, 33S, 34S and 36S. Speaking about the outer electron shell, the atom has a 3s2 3p4 scheme. The radius of the atom is 0.104 nanometers.
The properties of sulfur are primarily divided into physical types. This includes the fact that the element has a solid crystalline composition. Two allotropic modifications are the basic state in which this sulfur element is stable.
The first modification is rhombic, lemon-yellow in color. Its stability is lower than 95.6 °C. The second is monoclinic, having a honey-yellow color. Its resistance ranges from 95.6 °C and 119.3 °C.
During smelting, the chemical element becomes a moving liquid that is yellow in color. It turns brown, reaching temperatures of more than 160 °C. And at 190 °C the color of sulfur turns into dark brown. After reaching 190 °C, a decrease in the viscosity of the substance is observed, which nevertheless becomes liquid after heating to 300 °C.
Other properties of sulfur:
- Practically does not conduct heat or electricity.
- Does not dissolve when immersed in water.
- It is soluble in ammonia, which has an anhydrous structure.
- It is also soluble in carbon disulfide and other organic solvents.
It is important to add its chemical characteristics to the characteristics of sulfur. She is active in this regard. If sulfur is heated, it can simply combine with almost any chemical element.
With the exception of inert gases. Upon contact with metals, chemicals. the element forms sulfides. Room temperature allows the element to react with mercury. Increased temperature increases the activity of sulfur.
Let's consider how sulfur behaves with individual substances:
- With metals it is an oxidizing agent. Forms sulfides.
- Active interaction occurs with hydrogen at high temperatures - up to 200 ° C.
- With oxygen. Oxides form at temperatures up to 280 °C.
- With phosphorus, carbon - it is an oxidizing agent. Only if there is no air during the reaction.
- With fluorine it acts as a reducing agent.
- With substances that have a complex structure - also as a reducing agent.
Sulfur deposits and production
The main source for obtaining sulfur is its deposits. In total, there are 1.4 billion tons of reserves of this substance worldwide. It is mined both by open and underground mining and by smelting from underground.
If the latter case applies, then water is used, which is overheated and melts the sulfur with it. In low-grade ores, the element is contained in approximately 12%. Rich - 25% and more.
Common types of deposits:
- Stratiform - up to 60%.
- Salt dome - up to 35%.
- Volcanogenic - up to 5%.
The first type is associated with strata called sulfate-carbonate. At the same time, ore bodies that have a thickness of up to several tens of meters and a size of up to hundreds of meters are located in sulfate rocks.
Also, these strata deposits can be found among rocks of sulfate and carbonate origin. The second type is characterized by gray deposits, which are confined to salt domes.
The latter type is associated with volcanoes that have a young and modern structure. In this case, the ore element has a sheet-like, lens-shaped shape. It may contain sulfur in the amount of 40%. This type of deposit is common in the Pacific volcanic belt.
Sulfur deposit in Eurasia is located in Turkmenistan, the Volga region and other places. Sulfur rocks are found near the left banks of the Volga, which stretch from Samara. The width of the rock strip reaches several kilometers. Moreover, they can be found all the way to Kazan.
Various methods are used to extract sulfur. It all depends on the conditions of its occurrence. At the same time, of course, special attention is paid to safety.
Since hydrogen sulfide accumulates along with sulfur ore, it is necessary to take a particularly serious approach to any mining method, because this gas is poisonous to humans. Sulfur also tends to ignite.
Most often they use the open method. So, with the help of excavators, significant parts of the rocks are removed. Then the ore part is crushed using explosions. The lumps are sent to the factory for enrichment. Then - to the sulfur smelting plant, where sulfur is obtained from concentrate.
In the case of deep occurrence of sulfur in many volumes, the Frasch method is used. The sulfur melts while still underground. Then, like oil, it is pumped out through a broken well. This approach is based on the fact that the element melts easily and has a low density.
A separation method using centrifuges is also known. Only this method has a drawback: sulfur is obtained with impurities. And then it is necessary to carry out additional cleaning.
In some cases, the borehole method is used. Other possibilities for extracting the sulfur element:
- Steam-water.
- Filtration.
- Thermal.
- Centrifugal.
- Extraction.
Application of sulfur
Most of the mined sulfur is used to make sulfuric acid. And the role of this substance is very huge in chemical production. It is noteworthy that to obtain 1 ton of sulfuric substance, 300 kg of sulfur is needed.
Sparklers, which glow brightly and have many dyes, are also made using sulfur. The paper industry is another area where a significant portion of the extracted substance goes.
Most often, sulfur is used to satisfy industrial needs. Here are some of them:
- Use in chemical production.
- For the production of sulfites, sulfates.
- Production of substances for fertilizing plants.
- To obtain non-ferrous types of metals.
- To give steel additional properties.
- For making matches, materials for explosions and pyrotechnics.
- Paints and fibers from artificial materials are produced using this element.
- For bleaching fabrics.
In some cases, sulfur is included in ointments that treat skin diseases.
GOST 127.1-93
Group L11
INTERSTATE STANDARD
TECHNICAL SULFUR
Specifications
Sulfur for industrial use. Specifications
OKP 21 1221
21 1222
OKS 71.060
Date of introduction 1997-01-01
Preface
1 DEVELOPED by the Research and Design Institute of the Sulfur Industry with a pilot plant, Ukraine
INTRODUCED by the Technical Secretariat of the Interstate Council for Standardization, Metrology and Certification
2 ADOPTED by the Interstate Council for Standardization, Metrology and Certification on October 21, 1993 (Order No. 1 to Protocol No. 4-93)
The following voted for adoption:
State name | Name of the national standardization body |
Republic of Armenia | Armgosstandard |
Republic of Belarus | Belstandart |
The Republic of Kazakhstan | Gosstandart of the Republic of Kazakhstan |
The Republic of Moldova | Moldovastandard |
Russian Federation | Gosstandart of Russia |
Turkmenistan | Turkmen State Inspectorate |
The 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 March 21, 1996 N 198, the interstate standard GOST 127.1-93 was put into effect directly as a state standard on January 1, 1997.
4 INSTEAD GOST 127-76 (regarding sections 1, 2, 3, 5, 6)
INFORMATION DATA
REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS
Number of paragraph, subparagraph |
|
This standard applies to natural technical sulfur obtained from native sulfur and polymetallic sulfide ores, and industrial gas sulfur obtained from the purification of natural and coke oven gases, as well as waste gases from oil and shale processing.
Technical sulfur is used for the production of sulfuric acid, carbon disulfide, dyes, in pulp and paper, textile and other industries and for export.
The requirements of this standard are mandatory.
1 TECHNICAL REQUIREMENTS
1 TECHNICAL REQUIREMENTS
1.1 Technical sulfur must be produced in accordance with the requirements of this standard according to technological regulations approved in the prescribed manner.
1.2 Technical sulfur is produced liquid and lump.
1.3 Technical sulfur codes according to OKP are given in the appendix.
1.4 In terms of physical and chemical indicators, technical sulfur must comply with the standards specified in Table 1.
Table 1
Indicator name | |||||
Grade 9995 | Grade 9990 | Grade 9950 | Grade 9920 |
||
1 Mass fraction of sulfur, %, not less | |||||
2 Mass fraction of ash, %, no more | |||||
3 Mass fraction of organic substances, %, no more | |||||
4 Mass fraction of acids in terms of sulfuric acid, %, no more | |||||
5 Mass fraction of arsenic, %, no more | |||||
6 Mass fraction of selenium, %, no more | |||||
7 Mass fraction of water, %, no more | |||||
8 Mechanical contamination (paper, wood, sand, etc.) | Not allowed |
||||
Notes
1 Standards for indicators 1-6 are given in terms of dry matter;
2 The mass fraction of ash for liquid sulfur of grade 9998 should be no more than 0.008%, grades 9995 and 9990 no more than 0.01%;
3 The mass fraction of arsenic and selenium in natural sulfur obtained from native sulfur ores and in gas sulfur obtained during the purification of natural gases, as well as waste gases from oil refining, is not determined. In technical gas sulfur grade 9920 produced by coke-chemical enterprises, by agreement with the consumer, the mass fraction of arsenic is allowed to be no more than 0.05%;
4 The mass fraction of selenium in sulfur intended for the pulp and paper industry should be no more than 0.000%;
5 The mass fraction of water in liquid sulfur is not standardized. In lump sulfur, it is allowed to increase the mass fraction of water to 2% with the recalculation of the actual mass of the batch to the standardized humidity;
6 Lump sulfur intended for export must not contain pieces larger than 200 mm.
1.5 Indicators for items 4-6 of the table are determined at the request of the consumer or regulatory organization.
1.6 Example of designation when ordering:
Technical gas liquid sulfur, grade 9998, GOST 127.1-93.
2 SAFETY REQUIREMENTS
2.1 Sulfur is flammable. Dust suspended in the air is a fire and explosion hazard. The lower concentration limit of flame propagation (ignition) is 17 g/m; auto-ignition temperature - 190 °C according to GOST 12.1.041.
Hydrogen sulfide released from liquid sulfur explodes at a volume concentration of 4.3 to 45%; auto-ignition temperature - 260 °C.
2.2 Sulfur belongs to the 4th hazard class (GOST 12.1.005).
Sulfur causes inflammation of the mucous membranes of the eyes and upper respiratory tract, irritation of the skin, and diseases of the gastrointestinal tract; does not have cumulative properties.
Hydrogen sulfide is a poison that has a strong effect on the central nervous system.
Sulfur dioxide, which is formed when sulfur burns, causes irritation of the mucous membranes of the nose and upper respiratory tract.
Maximum permissible mass concentrations in the air of the working area: sulfur - 6 mg/m; sulfur dioxide - 10 mg/m; hydrogen sulfide - 10 mg/m.
2.3 Production premises and laboratories in which work with technical sulfur is carried out must be equipped with supply and exhaust mechanical ventilation, ensuring compliance with the maximum permissible concentrations of harmful substances in the air of the working area.
Air control of the working area must be carried out in accordance with the requirements of GOST 12.1.005 using methods approved by the Ministry of Health.
2.4 All workers must be provided with special clothing and personal protective equipment in accordance with GOST 12.4.011.
3 ACCEPTANCE RULES
3.1 Sulfur is subjected to acceptance tests.
3.2 Sulfur is accepted in batches. A batch is considered to be the amount of sulfur shipped to one address and accompanied by one quality document.
When transporting by water, each transport unit (barge, motor ship, tanker) is taken as a shipment of sulfur.
3.3 The quality document must contain the following data:
- name of the manufacturer and (or) its trademark;
- name and type of product;
- batch number and date of shipment;
- numbers of railway cars or other vehicles (for direct deliveries);
- test results or confirmation of product compliance with the requirements of this standard;
- net weight;
- danger sign 4a and classification code 4133 according to GOST 19433;
- UN serial number: for lump sulfur - 1350; for liquid - 2448;
- signature and stamp of the technical control department;
- designation of this standard.
3.4 To control the quality of lump and liquid sulfur, samples are taken from every fourth car (tank) of the controlled batch, but not less than from three cars (tanks).
When sending sulfur in a volume of less than three transport units, samples are taken from each transport unit.
When shipping sulfur by water transport, it is allowed to take samples during loading (unloading) of barges.
4 TEST METHODS
4.1 Sampling and preparation of samples is carried out in accordance with GOST 127.3.
4.2 Tests are carried out in accordance with GOST 127.2.
4.3 The presence of mechanical contamination is determined visually.
5 TRANSPORTATION AND STORAGE
5.1 Lump sulfur is transported in bulk in gondola cars with bottom hatches, as well as by road and water transport. By agreement with the consumer, it is allowed to transport sulfur in covered wagons. Car doors must be closed with safety panels.
Loading sulfur into contaminated vehicles is not allowed.
Liquid sulfur is transported in special heated railway tanks, used only for the transportation of liquid sulfur. Transportation is carried out in accordance with the instructions for operation and maintenance of railway tanks.
5.2 Transportation of sulfur intended for export is carried out in accordance with the requirements of this standard or contract.
5.3 Lump sulfur is stored under a canopy or in open areas.
To avoid sulfur contamination, sites must be provided with industrial and storm sewerage.
Liquid sulfur is stored in special insulated containers equipped with heating and pumping devices, as well as measuring instruments and exhaust pipes.
The containers must be labeled "LIQUID SULFUR".
6 MANUFACTURER WARRANTY
The manufacturer guarantees the compliance of technical sulfur with the requirements of this standard subject to the conditions of transportation and storage.
The guaranteed shelf life of technical sulfur is one year from the date of shipment.
APPENDIX (reference). OKP codes for technical sulfur
APPLICATION
(informative)
Product name | OKP code | |
Technical natural sulfur | ||
Technical natural lump sulfur | ||
21 1221 0110 | ||
21 1221 0120 | ||
21 1221 0130 | ||
grade 9920 | ||
Technical natural liquid sulfur | ||
21 1221 1010 | ||
21 1221 1020 | ||
Technical gas sulfur | ||
Technical gas sulfur lump | ||
21 1222 0110 | ||
21 1222 0120 | ||
grade 9990 | ||
grade 9950 | 21 1222 0140 | |
grade 9920 | 21 1222 0150 | |
Technical gas liquid sulfur | 21 1222 1000 | |
21 1222 1010 | ||
21 1222 1020 | ||
21 1222 1030 |
The text of the document is verified according to:
official publication
Technical sulfur: Sat. GOST. -
M.: IPK Standards Publishing House, 1996
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STATE STANDARD OF THE USSR UNION
TECHNICAL SULFUR
3.4.2. Carrying out analysis
(50 ± 1) g of sulfur is weighed, recording the weighing result in grams accurate to three decimal places, placed in a glass with a capacity of 400 cm 3, moistened with 25 cm 3 of ethyl alcohol and added 200 cm 3 of water. The contents of the glass are mixed, the glass is covered with a watch glass and boiled for 15-20 minutes, stirring occasionally. After cooling, the contents of the glass are filtered through a folded paper filter into a volumetric flask with a capacity of 250 cm 3, the volume of the solution is adjusted to the mark with water that does not contain CO 2, and mixed thoroughly. 100 cm 3 of the filtrate is taken into a conical flask with a capacity of 250 cm 3 and titrated from a burette with a solution of potassium or sodium hydroxide in the presence of phenolphthalein until the color is light pink.
At the same time, a control experiment is carried out with a solution containing water and alcohol under the same conditions and with the same amount of reagents, but without the analyzed product.
3.4.3. Processing the results
The mass fraction of acids in terms of sulfuric acid (.X 2) as a percentage is calculated using the formula
v _ (^i - V 2) K * 0.00049 250 100
where V x is the volume of sodium or potassium hydroxide solution consumed for titration of the analyzed solution, cm 3 ;
K 2 - volume of sodium or potassium hydroxide solution consumed for titration of the control sample solution, cm 3.
0.00049 - mass of sulfuric acid corresponding to 1 cm 3 solution of sodium or potassium hydroxide with a concentration of exactly 0.01 mol/dm 3, g;
m is the mass of the sulfur sample, g;
K is a correction factor for bringing the concentration of a solution of sodium or potassium hydroxide to exactly 0.01 mol/dm 3 .
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the absolute permissible values of the differences between them, as well as the absolute values of the total error of the analysis result, should not exceed the values specified in table. 6.
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Table 6 |
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3.4.1. -3.4.3.
3.5. Determination of the mass fraction of organic substances
The mass fraction of organic substances is determined by the gas-volume or spectral method (by total carbon) or by the gravimetric method by the loss of organic substances during ignition.
3.5.1. Gas volumetric method 3.5.1a. Essence of the method
The method is based on burning a sulfur sample in a furnace in a stream of oxygen and absorbing the released carbon dioxide with a solution of potassium hydroxide (Figure 1).
3.5.1.1. Equipment, reagents, solutions:
laboratory resistance electric furnace of the SNOL type, providing a stable temperature of the nargev (900 ± 10) °C; stopwatch according to GOST 5072-79; pipette according to GOST 20292-74;
asbestos calcined at a temperature of (800 ± 25) °C is stored in a desiccator;
|
Installation for carbon determination |
|
1 - oxygen cylinder 2 - reducer; 3 - gasometer or rotameter according to GOST 1304S-81; 4 - bottle SPZh - 250 according to GOST 25336-82; 5 - bottle 3 - 0.5 according to GOST 25 336-82; 6 - connecting glass tap KIX according to GOST 7995-80; 7.14 - plug; 8 - a tube made of transparent quartz glass or porcelain; 9 - SUOL oven - 0.25.1/12-Ml; 10.11 - boat LS 2 according to GOST 9147-80; 12 - copper mesh or copper wire MM-0.5 according to GOST 2112-79; 13 - oven TK-25-200; 15 - tube TX-U-2 -100 according to GOST 25336-82; 16 - bottle SN - 2 according to GOST 25336-82; 17 - bottle SN - 1 - 100 according to GOST 25336-82; 18-32 - gas analyzer GOU-1 according to GOST |
sulfur comparison sample containing 0.03% carbon for sulfur grades 9998,9995, 9990 and 9985 and 0.15% for other grades.
(Changed edition, Amendment No. 2).
3.5.1.1a. Preparing the installation for anaaisis
A quartz or porcelain tube 8 is inserted into furnaces 9 and 75, which should protrude from the furnaces by at least 175 mm on each side. Both ends of the pipe are closed with plugs 7 and 74, into the holes of which one-way glass taps are inserted b.
In pipe 8 of furnace 75, between asbestos plugs, a copper mesh 12 is placed, rolled up in the form of a cylinder, sprinkled with calcium silicate that does not contain CO 2. Instead of a mesh, you can use copper wire
drawing wire, copper filings or copper oxide.
To burn the sulfur sample, oxygen is supplied to the furnace from a cylinder 7 with a reducer 2 or from a gasometer 5. The oxygen is purified by passing through a Tishchenko flask 4 containing a solution of potassium permanganate with mass
fractions of 5% in a solution of potassium hydroxide with a mass fraction of 35%, then through column 5 for dry absorbents, filled at the bottom with glass beads, and at the top with roundworm and calcium chloride, separated by glass or absorbent wool. The oxygen supply is regulated by tap b #
Gases from the furnace to remove sulfur combustion products are passed sequentially through a U-shaped tube 15 filled with glass or hygroscopic wool (to retain solid particles entrained by the gas and condensing sulfuric acid mist), through a buffer vessel 16, which prevents the transfer of chromic anhydride into the U- shaped tube 15, through two absorption vessels 17 containing 50 cm 3 of a solution of chromic anhydride in sulfuric acid. After this, the gas enters a gas analyzer of the GOU-1 type to measure the volume of carbon dioxide.
A gas analyzer of type GOU-1 consists of a gas measuring burette (eudiometer) 1 24 with a capacity of 250 cm 3 with an automatic float shutter 22, a thermometer 23 and a scale 26, a refrigerator 25 and an absorption vessel 18 filled with a solution of potassium hydroxide and equipped with an automatic float shutter 22. The scale divisions show the percentage of carbon in sulfur in a 1 g sample.
Burette 24 has double walls (jacket), the space between which is filled with water through a special hole at the top of the burette to maintain a constant temperature.
The equalization bottle 27 has a side tube 31, closed with a stopper 32. The bottle 27 is filled with 400 to 500 cm 3 of an aqueous solution of sodium sulfate and closed with a rubber stopper 29, into the hole of which a three-way valve 28 with a rubber bulb 30 is inserted. Using the bulb, the gas mixture is pumped from burettes 24 into absorption vessel 18 and back.
(Introduced additionally, Amendment No. 2).
3.5 L.2. Preparing the instrument for analysis
Before starting operation, furnaces 9 and 13 are heated to a temperature of (850 ± 50) °C and (525 ± 25) °C, respectively. Check all connections and taps for leaks and bring the device into working condition. To do this, the valve 21 of the comb 19 is placed in a position in which the burette 24, the absorption vessel 18 and the refrigerator 25 are disconnected from each other. Having opened the valve 20 to connect the burette 24 to the atmosphere, using the equalizing bottle 27 and the bulb 30, fill the burette 24 with barrier liquid (in this case, the valve 28 of the equalizing bottle 27 is placed in the position of isolation from the atmosphere, and the tube 31 is closed with a stopper 32).
As soon as the liquid fills the burette 24, the valve 20 is closed, the valve 21 is placed in a position in which the burette 24 is connected to the absorption vessel 18. The valve 28 of the equalizing flask 27 is placed in connection with the atmosphere, while the liquid from the burette 24 begins to flow into the flask.
ku 27, the level of alkali solution in the absorption vessel 18 increases, raising the float 22.
As soon as the float closes the outlet from the absorption vessel 18, the valve 21 of the comb 19 is placed in a position in which the burette 24, the absorption vessel 18 and the refrigerator 25 are disconnected from each other. The small tap 20 is again placed at the connection of the burette with the atmosphere and, in the same way as indicated above, using the equalizing flask 27, tap 28 and bulb 30, the burette 24 is filled with liquid to the upper limit (the float closes the exit from the burette).
When the burette 24 is filled with liquid, the valve 20 is closed, and the valve 28 of the equalizing flask 27 is connected to the atmosphere.
If the device is sealed, then the absorption vessel 18 remains filled, and the liquid level in the burette remains unchanged. The constancy of the level is observed when the liquid is in the narrow part of the burette 24; the reading is carried out according to the divisions of the scale 26.
If the solution levels drop, then the device is not sealed; it should be disassembled, the taps wiped, lubricated with Vaseline and checked again for leaks.
After making sure that the device is sealed, a control determination of the sulfur reference sample is carried out.
(Changed edition, Amendment No. 2).
3.5.1.3. Analysis conditions
The measuring burette must be thoroughly cleaned of contamination by rinsing with a chrome mixture and then with distilled water.
When reading the burette scale, you must always bring the tube 31 of the equalizing flask 27 to the burette in the same way, holding it so that the liquid is always at the same level. The hose connecting the burette to the equalizing flask must always be in the same position and not hang down from the table.
Readings of the burette can be carried out only after 15-20 seconds of exposure (measured using a stopwatch), so that the liquid can completely drain from the walls.
When 8 drops of sulfuric acid appear in the tube, calcium silicate (barium) is replaced with fresh one.
Porcelain or quartz boats 80-100 mm long are calcined in an oven at 800-900°C and stored in a desiccator.
3.5 L.4. Carrying out analysis
Before starting work, three boats 10 ts 11 with calcium silicate (barium) are pushed into the combustion tube 8 using a copper hook through the hole for the plug 7 and the heating of furnaces 9 and 13 is turned on.
As soon as the furnaces are heated to the appropriate temperatures, the gas analyzer is placed in the working position, and tube 8 is connected with plugs 7 and 14 to U-shaped tube 75 and tap 6, after which a control experiment is carried out, i.e. pass a current of oxygen through a heated tube 8 and observe the readings on the scale 26 of the burette 24 before and after the absorption of carbon dioxide.
As soon as carbon disappears from the system, the difference in scale readings before and after the absorption of carbon dioxide will be zero or will give the same value (1-2 scale divisions), which is subtracted in the calculation. Then the operation of the device is checked using a sulfur comparison sample, for this, boats 10 and 11 are removed from tube 8 of furnace 9, 0.3 - 0.5 g of a sulfur comparison sample is placed in boat 10, calcium silicate (barium) is poured over Boats 10 and 11 quickly push it into tube 8 of oven 9 using a hook and close the tube with rubber stopper 7. Open tap 6 and pass a current of oxygen from gasometer 3 at a speed of 4 - 5 bubbles per second. The valve 21 must be adjusted so that the discharge of the barrier liquid from the burette 24 into the flask 27 occurs evenly (filling the burette 24 with gases should last about 1-1.5 minutes). In this case, the valve 28 of the equalizing flask 27 is placed in connection with the atmosphere.
As soon as the narrow (lower) part of the burette is filled with gases and the liquid level reaches the zero division of scale 26, valve 21 is placed in the position of disconnection from the refrigerator 25, burette 24 and absorber 18, the oxygen supply is stopped (the valve 6 is closed), the liquid is allowed to drain from the walls and After 15 - 20 s, the volume of the resulting gas mixture is measured. To do this, remove the stopper 32 from the tube 31 of the bottle 2 7 and, moving the bottle 27 at the appropriate position of the valve 28 along the burette (next to it), reach a position at which the liquid levels in the burette 24 and the tube 31 of the bottle 27 are at the same level. The readings of the scale 26 are recorded, the tube 31 is closed with a stopper 32. The flask 27 is disconnected from the atmosphere with a tap 28, the burette 24 is connected to the vessel 18 by turning the tap 21, and with the help of a bulb 30 the gaseous products are transferred 2-3 times from the burette 24 to the absorption vessel 18 and back. When transferring gas to burette 24, valve 28 of the equalizing flask is placed in the position of communication with the atmosphere. Record the scale readings. The difference in readings before and after absorption of CO 2 indicates the volume of absorbed carbon dioxide. After measuring the volume of absorbed carbon dioxide using tap 20, the burette is emptied of gas, filled with a barrier liquid, and secondary combustion is carried out. The determination is considered complete if, during the control combustion of the sample, the difference in the counts before and after the absorption of CO 2 is equal to zero. At the end of each test, temperature and atmospheric pressure are measured and, using the table attached to the device, a correction is found for the conditions under which the carbon determination was carried out.
3.5 L.5 o Processing of results
The mass fraction of carbon (X 3) as a percentage is calculated using the formula
where V is the volume of carbon dioxide, expressed as a percentage of carbon; K - correction for temperature and pressure; m is the mass of the sulfur sample, g.
The mass fraction of organic matter (X 4) as a percentage is calculated using the formula
X 4 = X b 1.25,
where X ъ is the mass fraction of carbon, %;
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the absolute permissible differences between which, as well as the absolute total error of the analysis results, should not exceed the values specified in table. 7.
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Table 7 |
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The gas-volume method for determining carbon content is arbitrary.
3.5.2. Spectral method 3.5.2a. Essence of the method
The method is based on photographing sample spectra and determining total carbon using a calibration curve.
3.5.2.1. Equipment, materials and reagents ISP-30 spectrograph with a single-line quartz condenser; AC arc generator DG-2 in low-voltage spark mode; microphotometer type IFO-451 or MF-2, MF-4;
aluminum electrodes, AD-1 grade, 6 mm in diameter. A cylindrical channel is drilled at the ends of the electrodes, with an outer diameter of 3 mm, an inner diameter of 2.5 mm, and a depth of 3-5 mm. For operation, two electrodes filled with sample are used. Aluminum electrodes, made on a lathe or using a stamp, are wiped and washed in acetone or benzene to remove traces of lubricating oils, dried under traction and then fired on an aluminum baking sheet in a muffle furnace at (500 ± 10) ° C for 20 minutes to removing traces of organic compounds. After cooling, the electrodes are placed in a closed glass jar and stored in a dry place;
an aluminum plate measuring 24X70X10 mm for dosing the filling of electrodes with samples, in which a flat recess 8 mm deep and 16X16 mm in size was made with a milling cutter;
aluminum foil for storing samples;
agate or chrome-plated steel mortar with a diameter of 90 mm; sulfur wasps Part 16-5;
laboratory resistance electric furnace type SNOL in accordance with GOST 13474-79, providing a stable heating temperature (900 ± 10) ° C;
drying cabinet type SNOL, providing a stable heating temperature (80 ± 2) ° C; aluminum ruler; cup SN-85/15 according to GOST 25336-82; acetone according to GOST 2603-79; benzene according to GOST 5955-75; sieve 0071 according to GOST 6613-86.
3.5.2 2. Preparation of the main sample
The main sample used is sulfur, crushed and sifted through a sieve, with a mass fraction of organic carbon of 0.3 - 0.6%, from which volatile fractions of organic substances are first removed (the sulfur sample is kept in a drying oven at a temperature of (80 ± 2) ° C to constant mass).
In the main sample, carbon is determined by the chemical gas-volume method, repeating the determination 10 times. The arithmetic mean of 10 determinations is taken as the true carbon content.
3.5.2.3. Preparation of reference samples
Comparison samples are prepared by mixing the sulfur of the main sample with sulfur of the wasp grade. h., previously crushed and sifted through a sieve. For this, a sample of sulfur from the main sample weighing 20; 6 and 2 g are thoroughly mixed in a mortar, respectively, with weighed portions of special grade sulfur. weighing 40; 54th 58. The results of all weighings in grams are recorded with an accuracy of three decimal places. The mass fraction of carbon in the first sample is 0.1 - 0.2%, in the second sample - 0.03-0.06% and in the third sample -0.01-0.02%.
Samples are stored in glass cups with ground-in stoppers.
3.5.2 in 4. Conducting analysis
The analyzed sulfur samples, crushed and sifted through a sieve, and reference samples are introduced into the electrodes (upper and lower), for which the sample is placed in a dosing plate in an even layer, rising above the plate by 3 - 5 mm, before shooting.
Using the edge of an aluminum ruler, make 5-6 consecutive cuts of excess powder in the form of a rectangular mesh, then cut off the excess powder with the same ruler. The electrode is pressed into the layer of powder until it stops at the bottom of the plate and is removed from it with a slight turn.
A low-voltage spark with a current of 6 A is ignited between the electrodes. The distance between the electrodes is 2 mm, the exposure is 25 s.
The spectra of samples and reference samples are photographed three times with a spectrograph at a slit width of 0.01 mm.
The darkening of the analytical line is measured on the resulting spectrograms.
Based on the results of photometric measurements of the spectra of comparison samples, calibration graphs are constructed in AS-lgC coordinates. Based on the results of photometry of sample spectra, the content of determined carbon in the analyzed sample is determined from calibration graphs. The arithmetic mean of three parallel determinations is taken as the result of the analysis.
3.5.2.5. Processing the results
The mass fraction of organic matter (T 4) in percent is calculated using the formula
X A = X 3 1.25,
where X-s is the mass fraction of carbon, %;
1.25 is the conversion factor of carbon to organic matter.
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the relative discrepancy between which does not exceed the permissible discrepancy of 30%.
The limits of permissible relative total error of the analysis result are ± 15%.
3.5.2.1-3.5.2.5. (Changed edition, Amendment No. 2).
3.5.3* Determination of organic substances by gravimetric method
3.5.3a. Essence of the method
The method is based on the gravimetric determination of the amount of the specified substance from the difference in mass after double calcination of the sample at temperatures (250 ± 10) ° C and (800 ± 10) ° C.
3.5*3. L Hardware:
laboratory resistance electric furnace of the SNOL type, providing a stable heating temperature (900 ± 10)°C;
sand bath.
It is allowed to use a low temperature heater 5 in accordance with GOST 9147-80 instead of a bowl, and a single-burner electric stove in accordance with GOST 14919-83 instead of a sand bath.
3.5.3.2, Conducting analysis
(50 ± 1) g of sample is placed in a bowl that has been previously calcined and weighed. The sample is melted and fired in a sand bath. Then the bowl with the residue is calcined at a temperature of (250 ± 10) °C for 2 hours to remove traces of sulfur.
The bowl containing the residue, consisting of organic matter and ash, is transferred to a desiccator, cooled and weighed. Then the bowl with the rest of the
put into an electric furnace, calcined at a temperature of (800 ± 10) °C to constant weight, cooled in a desiccator and weighed. The results of all weighings in grams are recorded with an accuracy of three decimal places.
3.5.3.3. Processing the results
The mass fraction of organic substances (X 4) as a percentage is calculated using the formula
(t x - t 2) ■ 100 t
where m is the mass of the analyzed sample, g;
m x - mass of the residue containing organic substances and ash, g; t 2 - mass of the residue after calcination in a muffle furnace, g.
The result of the analysis is taken as the arithmetic mean of the results of two parallel determinations, the relative discrepancy between which should not exceed the permissible discrepancy of 30%.
The limits of permissible relative total error of the analysis result are ± 15%.
3.5.3.1. -3.5.3.3. (Changed edition, Amendment No. 2).
3.6. Determination of the mass fraction of arsenic
3.6.1. Spectral method 3.6.1a. Essence of the method
The method is based on photographing sample spectra and determining arsenic using a calibration curve.
3.6.1.1. Equipment, materials and solutions: ISP-30 spectrograph with a single-lens lighting system; AC arc generator DG-2 in arc mode and mode
low voltage spark;
microphotometer type IFO-451 or MF-4, MF-2; devices for sharpening carbon electrodes; OS grade carbon electrodes. Part-7-4 or S-1. Lower and upper electrode with a crater with a diameter of 4 mm and a depth of 5 mm. Before analysis, coals are analyzed for the absence of arsenic lines in their spectra under the conditions of the analysis method. If an arsenic line is present, the electrodes are fired for 20 s in analysis mode;
a dosing plate made of organic glass for filling electrodes with a sample measuring 24X70X8 mm, in which a flat recess 6 mm deep and 16X16 mm in size was made with a milling cutter;
agate or chrome-plated steel mortar with a diameter of 90 mm;
quartz condenser (F-1S mm);
gas sulfur with arsenic content 0.4 - 0.6%;
sulfur wasps hours - 16-5;
spectrographic photographic plates type 3, spectral sensitivity in relative units equal to 9, spectrographic type 1,
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Continuation of the table. 1 |
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Notes:
1a. Sulfur grades 9995, 9990 and 9998 correspond to the highest quality category.
1. Standards for indicators 1-9 of the table are given in terms of dry matter.
2. Standards for indicators 6-9 of the table are given for ground sulfur.
3. It is allowed to increase the mass fraction of water to 2% in grades 9950 and 9920 with the recalculation of the actual mass of the batch to the standardized moisture content.
4. For liquid filtered sulfur of grades 9995 and 9990, the mass fraction of ash should not be more than 0.007%, for other grades no more than 0.015%. For liquid sulfur grade 9998, the mass fraction of ash should be no more than 0.008%.
5. Excluded.
6. For the production of carbon disulfide, the mass fraction of bitumen in natural sulfur of grade 9950 should not be more than 0.15%.
I. In ground natural sulfur of grades 9995 and 9990, intended for the rubber and tire industries, the mass fraction of water should not exceed 0.05%.
8. Natural sulfur intended for the pulp and paper industry must not contain selenium.
9. Subject to consumer requirements, to prevent caking and clumping, it is allowed to produce ground sulfur of all grades with the addition of aerosil (GOST 14922-77) or kaolin (GOST 21285-75 - GOST 21288-75) up to 0.5% by weight of sulfur without changing its grade.
10. The mass fraction of water in vein sulfur is not standardized.
II. In ground sulfur of the 2nd and 3rd classes intended for agriculture, the mass fraction of arsenic should not be more than 0.000%
(Changed edition, Amendments No. 1,2).
spectral sensitivity in relative units equal to 6, photographic plates of the UFSh-3 type, sensitivity 20 units;
technical ethyl alcohol according to GOST 18300-72, distilled;
3.6.1.2, Preparation of the main sample
The main sample used is gas sulfur with a mass fraction of arsenic from 0.3 to 0.6%, crushed and sifted through a sieve with a mesh size of 74 microns. The mass fraction of arsenic is determined by the photometric method, repeating the determination 10 times. The arithmetic mean is taken as the true content.
3.6.1.3. Preparation of reference samples
Comparison samples are prepared by sequentially mixing the sulfur of the main sample with sulfur of the wasp grade. h., previously crushed and sifted through a sieve.
To do this, weighed samples of sulfur of the main sample weighing 20 and 6 g are thoroughly mixed in a mortar under alcohol, respectively, with weighed samples of sulfur of the highest grade. h in mass 40 and 54 g.
The first and second comparison samples obtained in this way contain, respectively, from 0.1 to 0.2 and from 0.03 to 0.06% mass fraction of arsenic.
The third and fourth reference samples, containing respectively from 0.01 to 0.02 and from 0.003 to 0.006% mass fraction of arsenic, are prepared in a similar way, using 20 and 6 g of sulfur of the second comparison sample as a base. They are mixed with 40 and 54 g of wasp grade sulfur, respectively. h.
Using the sulfur of the fourth reference sample, prepare the fifth and sixth reference samples, containing, respectively, from 0.001 to 0.002 and from 0.0003 to 0.0006% mass fraction of arsenic, by mixing 20 and 6 g of the fourth reference sample, respectively, with 40 and 54 g of grade sulfur os. h.
The seventh comparison sample, containing from 0.0001 to 0.0002% of the mass fraction of arsenic, is prepared by mixing 20 g of sulfur of the sixth sample and 40 g of sulfur of wasp grade. h. The results of all weighings in grams are recorded accurate to the fourth decimal place.
To prepare one reference sample, 100 cm 3 of alcohol is used.
The obtained samples are stored in cups.
3.6A A. Conducting analysis
The analyzed sulfur samples are crushed, sifted through a sieve and introduced into the electrodes (upper and lower).
An alternating current arc is ignited between the electrodes from the DG-2 generator, with a current strength of 18 A (with an additional rheostat turned on - 11 Ohm;
1.1. Depending on the raw materials used, sulfur is divided into natural and gas and is produced in the following types: lump, ground, granular, flake and liquid.
(Changed edition, Amendment No. 2)
1.2. In terms of physical and chemical indicators, sulfur must comply with the standards specified in table. 1.
1.3. The granulometric composition of granulated and ground sulfur must comply with the standards specified in Table 2.
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table 2 |
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