GB/T 1918-2021_English: PDF (GB/T1918-2021)
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Standard ID | GB/T 1918-2021 (GB/T1918-2021) | Description (Translated English) | Potassium nitrate for industrial use | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | G12 | Classification of International Standard | 71.060.50 | Word Count Estimation | 18,170 | Date of Issue | 2021-08-20 | Date of Implementation | 2022-03-01 | Older Standard (superseded by this standard) | GB/T 1918-2011 | Drafting Organization | Jiangxi Jinlida Potassium Industry Co., Ltd., Qinghai Union University Chemical Technology Co., Ltd., Weifang Changsheng Nitrate Co., Ltd., Shandong Enersen New Material Technology Co., Ltd., Wentong Potash Group Co., Ltd., Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Wenshui County Zhenxing Fertilizer Co., Ltd., Jinka Technology Co., Ltd., Qinghai University for Nationalities, Jiaocheng County Bingsheng Chemical Co., Ltd., Jiangxi Jintai Chemical New Materials Co., Ltd., Shanxi Jinlan Chemical Co., Ltd., Hunan Meiao Potassium Industry Co., Ltd., Zhejiang Luye Water Purifier Technology Co., Ltd., CNOOC Tianjin Chemical Research and Design Institute Co., Ltd. | Administrative Organization | National Chemical Standardization Technical Committee Inorganic Chemical Sub-Technical Committee (SAC/TC 63/SC 1) | Proposing organization | China Petroleum and Chemical Industry Federation | Issuing agency(ies) | State Administration for Market Regulation, National Standardization Administration | Standard ID | GB 1918-2011 (GB1918-2011) | Description (Translated English) | [GB/T 1918-2011] Potassium nitrate for industrial use | Sector / Industry | National Standard | Classification of Chinese Standard | G12 | Classification of International Standard | 71.060.50 | Word Count Estimation | 14,139 | Date of Issue | 2011-12-05 | Date of Implementation | 2012-08-01 | Older Standard (superseded by this standard) | GB/T 1918-1998 | Quoted Standard | GB 190-2009; GB/T 191-2008; GB/T 685-1993; GB/T 3049-2006; GB/T 3051-2000; GB/T 6678; GB/T 6682-2008; GB/T 8170; GB/T 8946-1998; GB/T 23945-2009; HG/T 3696.1; HG/T 3696.2; HG/T 3696.3 | Drafting Organization | CNOOC Tianjin Chemical Research and Design Institute | Administrative Organization | National Standardization Technical Committee machines Chemical Chemistry Branch | Regulation (derived from) | Announcement of Newly Approved National Standards No. 19 of 2011 | Proposing organization | China Petroleum and Chemical Industry Federation | Issuing agency(ies) | Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China; Standardization Administration of China | Summary | This Chinese standard specifies the requirements for industrial potassium nitrate, test methods, inspection rules and signs, packaging, transportation, storage, and security. This standard applies primarily as a black powder, fuse, optical glass, ammonia catalysts, metal heat treatment, enamel and pharmaceutical intermediates for industrial raw materials such as potassium nitrate. | Standard ID | GB/T 1918-1998 (GB/T1918-1998) | Description (Translated English) | Potassium nitrate for industrial use | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | G12 | Classification of International Standard | 71.060.50 | Word Count Estimation | 10,133 | Date of Issue | 1998/10/20 | Date of Implementation | 1999/5/1 | Older Standard (superseded by this standard) | GB/T 1918-1986 | Quoted Standard | GB 190-1990; GB 191-1990; GB/T 601-1988; GB/T 602-1988; GB/T 603-1988; GB/T 685-1993; GB/T 1250-1989; GB/T 3049-1986; GB/T 3050-1982; GB/T 6678-1986; GB/T 6682-1002 | Adopted Standard | MIL-P-156B-1956 (1990), NEQ | Drafting Organization | Chemical Industry Ministry Tianjin Chemical Acedemy | Administrative Organization | Chemical Industry Ministry mineral products Standardization Technical focal point | Regulation (derived from) | Announcement of Newly Approved National Standards No. 19 of 2011 | Proposing organization | Ministry of Chemical Industry of the People Republic of China | Issuing agency(ies) | State Quality and Technical Supervision | Summary | This Standard specifies requirements for industrial potassium nitrate, test methods, inspection rules and signs, packaging, transportation and storage. This Standard is applicable to industrial nitrate, the products are mainly used black powder, fuse, optical glass, ammonia catalysts, metal heat treatment, etc., also applies to enamel and pharmaceutical raw materials for industrial use. |
GB/T 1918-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.060.50
CCS G 12
Replacing GB/T 1918-2011
Potassium Nitrate for Industrial Use
工业硝酸钾
ISSUED ON: AUGUST 20, 2021
IMPLEMENTED ON: MARCH 1, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Terms and Definitions ... 6
4 Molecular Formula and Relative Molecular Mass ... 6
5 Classification ... 6
6 Requirements ... 6
7 Test Methods ... 7
8 Inspection Rules ... 22
9 Marking and Labeling ... 23
10 Packaging, Transportation and Storage ... 24
Appendix A (informative) Commonly Used ICP-OES Spectral Lines and Detection
Limits ... 25
Bibliography ... 26
Potassium Nitrate for Industrial Use
WARNING: in accordance with the provisions of Chapter 6 in GB 12268-2012, this
product belongs to Category 5, Item 5.1 oxidizing substances, and caution shall be
exercised when handling it. Personnel using this document shall have practical experience
in formal laboratory work. This document does not point out all possible safety issues.
Users are responsible for taking appropriate safety and health measures and ensuring the
compliance with the conditions stipulated in relevant national regulations.
1 Scope
This document specifies the classification, requirements, test methods, inspection rules,
marking, labeling, packaging, transportation and storage of potassium nitrate for industrial use.
This document is applicable to potassium nitrate for industrial use.
NOTE: this product is mainly used in molten salt, black powder, fuses, pharmaceutical
intermediates, optical glass, ammonia catalyst, metal heat treatment, enamel and other
industries.
2 Normative References
The contents of the following documents constitute indispensable clauses of this document
through the normative references in the text. In terms of references with a specified date, only
versions with a specified date are applicable to this document. In terms of references without a
specified date, the latest version (including all the modifications) is applicable to this document.
GB/T 191-2008 Packaging - Pictorial Marking for Handling of Goods
GB/T 3051-2000 Inorganic Chemical Products for Industrial Use - General Method for
Determination of Chloride Content - Mercurimetric Method
GB/T 3600-2000 Fertilizers - Determination of Ammoniacal Nitrogen Content - Formaldehyde
Method
GB/T 6678 General Principles for Sampling Chemical Products
GB/T 6682-2008 Water for Analytical Laboratory Use - Specification and Test Methods
GB/T 8170 Rules of Rounding off for Numerical Values & Expression and Judgement of
Limiting Values
GB/T 23945-2009 Inorganic Chemicals for Industrial Use - General Method for the
Determination of Chloride Content - Visible Turbidimetric Method
HG/T 3696.1 Inorganic Chemicals for Industrial Use - Preparations of Standard and Reagent
Solutions for Chemical Analysis - Part 1: Preparations of Standard Volumetric Solutions
HG/T 3696.2 Inorganic Chemicals for Industrial Use - Preparations of Standard and Reagent
Solutions for Chemical Analysis - Part 2: Preparations of Standard Solutions for Impurity
HG/T 3696.3 Inorganic Chemicals for Industrial Use - Preparations of Standard and Reagent
Solutions for Chemical Analysis - Part 3: Preparations of Reagent Solutions
JT/T 617 (all parts) Regulations Concerning Road Transportation of Dangerous Goods
3 Terms and Definitions
This document does not have terms or definitions that need to be defined.
4 Molecular Formula and Relative Molecular Mass
Molecular formula: KNO3
Relative molecular mass: 101.10 (in accordance with the international relative atomic mass in
2018)
5 Classification
Potassium nitrate for industrial use is classified into three categories. The main purposes are as
follows:
---Category I products are mainly used for molten salt manufacturing;
---Category II products are divided into two types. Type I products are mainly used for the
manufacturing of black powder, fuses, pharmaceutical intermediates and glass clarifiers,
etc. Type II products are mainly used for metal heat treatment and the manufacturing
of enamel paint, etc.;
---Category III products are products added inorganic salts as anti-caking agents and are
mainly used as fluxes for glass and ceramics.
6 Requirements
6.1 Appearance: potassium nitrate for industrial use is white crystal or spherical particles.
6.2 Potassium nitrate for industrial use shall be tested in accordance with the test methods
specified in this document and shall comply with the stipulations of Table 1.
3696.1, HG/T 3696.2 and HG/T 3696.3.
7.2 Appearance Inspection
Under natural light, adopt the method of visual inspection for determination.
7.3 Determination of Potassium Nitrate Content
7.3.1 Principle
In neutral medium, potassium ions react with sodium tetraphenylborate to generate potassium
tetraphenylborate precipitate. If ammonium ions are present, formaldehyde solution can be
added to eliminate the interference of ammonium ions. In accordance with the mass of the
generated potassium tetraphenylborate, determine the potassium nitrate content. Its main
reaction formula is as follows:
7.3.2 Reagents or materials
7.3.2.1 Absolute ethanol.
7.3.2.2 Formaldehyde solution: filter before use.
7.3.2.3 Acetic acid solution: 1 + 100.
7.3.2.4 Sodium hydroxide solution: 4 g/L.
7.3.2.5 Sodium tetraphenylborate ethanol solution.
7.3.2.6 Saturated ethanol solution of potassium tetraphenylborate.
7.3.2.7 Methyl orange indicator solution: 1 g/L.
7.3.2.8 Phenolphthalein indicator solution: 10 g/L.
7.3.3 Instruments and equipment
7.3.3.1 Electric thermostatic drying oven: the temperature can be controlled at 120 C 2 C.
7.3.3.2 Glass sand crucible: with a filter plate pore size of 5 m ~ 15 m.
7.3.4 Test steps
7.3.4.1 Preparation of test solution
Weigh-take 1.0 g ~ 1.2 g of sample, accurate to 0.0002 g, place it in a 100 mL beaker. Add water
to dissolve it, transfer the solution to a 500 mL volumetric flask, use water to dilute to the scale
and shake it well.
7.3.4.2 Test
Use a pipette to transfer 25 mL of the test solution, place it in a 150 mL beaker, add 20 mL of
water and 2 drops of methyl orange indicator solution, and use acetic acid solution to adjust the
solution to just turn red. If it contains ammonium salt, add 1 ~ 2 drops of phenolphthalein
indicator solution and 2 mL of formaldehyde solution, and use sodium hydroxide solution to
adjust it to turn reddish. Use a constant-temperature water bath to heat the solution to 45 C
(continue to keep the solution in reddish, and if there is any precipitate, filter and thoroughly
wash it), while stirring, dropwise add 8 mL of sodium tetraphenylborate ethanol solution (the
dropping time is about 5 minutes) and continue stirring for 1 minute. After letting it stand for
30 minutes, use a glass sand crucible that has been dried to a constant mass in an electric
thermostatic drying oven at 120 C 2 C to suction filter it, use 20 mL of saturated ethanol
solution of potassium tetraphenylborate to transfer the precipitate, and use 15 mL of saturated
ethanol solution of potassium tetraphenylborate to wash the precipitate in 3 ~ 4 times (it shall
be drained each time). Then, use 2 mL of absolute ethanol to wash once along the inner wall of
the crucible, and drain it. In an electric thermostatic drying oven at 120 C 2 C, dry it, until
reaching a constant mass.
7.3.4.3 Test data processing
The potassium nitrate content, which is calculated as the mass fraction w1 of potassium nitrate
(KNO3), shall be calculated in accordance with Formula (1):
Where,
0.2822---the coefficient for converting potassium tetraphenylborate into potassium nitrate;
m2---the mass of the glass sand crucible and the potassium tetraphenylborate precipitate after
drying to a constant mass, expressed in (g);
m1---the mass of the glass sand crucible after drying to a constant mass, expressed in (g);
m---the mass of the sample, expressed in (g);
V1---the volume of the test solution taken in 7.3.4.2, expressed in (mL);
V---the volume of the test solution taken in 7.3.4.1, expressed in (mL);
w2---the moisture content determined in 7.4;
3.37---the coefficient for converting carbonate to potassium nitrate;
w6---the mass fraction of carbonate determined in 7.8.
Take the arithmetic mean of the parallel determination results as the determination result. The
Transfer all into a 500 mL (V1) volumetric flask, use water to dilute to the scale and shake it
well. This solution is test solution A, which is used for the determination of chloride, sulfate,
carbonate and ammonium salt content.
7.6.1.4.2 Preparation of reference solution
Add 50 mL of water to a 250 mL conical flask, add 3 g of urea, and heat to dissolve it. At a
slight boil, dropwise add nitric acid (1 + 1) solution, until no fine bubbles are generated, then,
cool it. Add 2 ~ 3 drops of bromophenol blue indicator solution, use sodium hydroxide (1 mol/L)
solution to adjust the solution, until it turns blue, then, use nitric acid (1 mol/L) solution to
adjust the solution, until it turns from blue to yellow, then, add an overdose of 2 ~ 6 drops. Add
1.0 mL of phenylazoformic acid 2-phenylhydrazide indicator solution, and use a microburette
to titrate it with a mercury nitrate standard titration solution with a concentration c [1/2
Hg(NO3)2] of 0.05 mol/L, until the solution turns purple red. Record the volume (V0) of the
mercury nitrate standard titration solution used. Prepare this solution before use.
7.6.1.4.3 Test
Use a pipette to transfer 50 mL (V2) of test solution A (see 7.6.1.4.1), place it in a 250 mL
conical flask. Add 3 g of urea and heat to dissolve it. At a slight boil, dropwise add nitric acid
(1 + 1) solution, until no fine bubbles are generated, then, cool it. Add 2 ~ 3 drops of
bromophenol blue indicator solution, use sodium hydroxide (1 mol/L) solution to adjust the
solution, until it turns blue. Then, use nitric acid (1 mol/L) solution to adjust the solution, until
it turns from blue to yellow, then, add an overdose of 2 ~ 6 drops. Add 1.0 mL of
phenylazoformic acid 2-phenylhydrazide indicator solution, and use a mercury nitrate standard
titration solution with a concentration c [1/2 Hg(NO3)2] of 0.05 mol/L to titrate it, until the
solution turns from yellow to purple red, which is the same as the reference solution, which is
the end point. The treatment of mercury-containing waste liquid shall be carried out in
accordance with Appendix D of GB/T 3051-2000.
7.6.1.5 Test data processing
Chloride, which is calculated as the mass fraction w4 of chlorine (Cl), shall be calculated in
accordance with Formula (4):
Where,
V---the volume of the mercury nitrate standard titration solution consumed during the
determination, expressed in (mL);
V0---the volume of the mercury nitrate standard titration solution consumed when preparing the
reference solution, expressed in (mL);
c---the accurate value of the concentration of the mercury nitrate standard titration solution,
expressed in (mol/L);
M---the numerical value of the molar mass of chloride (calculated as Cl), expressed in (g/mol)
[M(Cl) = 35.45];
m---the mass of the sample contained in test solution A (see 7.6.1.4.1) in 7.6.1.4.1, expressed
in (g);
V2---the volume of test solution A (see 7.6.1.4.1) transferred in 7.6.1.4.3, expressed in (mL);
V1---the volume of test solution A (see 7.6.1.4.1) in 7.6.1.4.1, expressed in (mL).
Take the arithmetic mean of parallel determination results as the determination result. The
absolute difference between two parallel determination results shall not be greater than 0.002%.
7.6.2 Visible turbidimetric method
7.6.2.1 Principle
Same as Chapter 3 of GB/T 23945-2009.
7.6.2.2 Reagents or materials
Same as Chapter 6 of GB/T 23945-2009.
7.6.2.3 Test steps
Use a pipette to transfer 5 mL of test solution A (see 7.6.1.4.1) into a 50 mL colorimetric tube,
add water to approximately 40 mL, add 1.0 mL of nitric acid solution and 1.0 mL of silver
nitrate solution. Use water to dilute to the scale and shake it well, then, let it stand for 10 minutes.
If the white turbidity generated is deeper than the standard turbidity solution, then, it does not
comply with the indicator requirements specified in this document, otherwise, it complies with
the indicator requirements specified in this document.
The standard turbidity solution is to pipette (Category I: 1.00 mL; Category II Type I, Category
II Type II and Category III: 2.00 mL) chloride standard solution [1 mL contains 0.10 mg of
chlorine (Cl)], and handle it at the same time in the same way as the test solution.
7.7 Determination of Sulfate Content
7.7.1 Gravimetric method (arbitration method)
7.7.1.1 Principle
Sulfate can react with barium ions to generate barium sulfate precipitate under acidic conditions.
Weigh the mass of the generated barium sulfate. The main reaction formula is as follows:
m---the mass of the sample contained in test solution A (see 7.6.1.4.1) in 7.6.1.4.1, expressed
in (g);
V2---the volume of test solution A (see 7.6.1.4.1) transferred in 7.7.1.4, expressed in (mL);
V1---the volume of test solution A (see 7.6.1.4.1) in 7.6.1.4.1, expressed in (mL).
Take the arithmetic mean of parallel determination results as the determination result. The
absolute difference between two parallel determination results shall not be greater than 0.005%.
7.7.2 Visible turbidimetric method
7.7.2.1 Principle
Sulfate can react with barium ions to generate barium sulfate precipitate under acidic conditions.
When the sulfate content is relatively low, a suspension is formed, which can be used for the
determination of sulfate content. Its main reaction formula is as follows:
7.7.2.2 Reagents or materials
7.7.2.2.1 Hydrochloric acid solution: 1 + 4.
7.7.2.2.2 Barium chloride solution: 100 g/L.
7.7.2.2.3 Sulfate standard solution: 1 mL of solution contains 0.1 mg of sulfate (SO4). Use a
pipette to transfer 10 mL of the sulfate standard solution prepared in accordance with HG/T
3696.2, place it in a 100 mL volumetric flask, use water to dilute to the scale and shake it well.
7.7.2.3 Test steps
Use a pipette to transfer 5 mL of test solution A (see 7.6.1.4.1) into a 100 mL colorimetric tube,
add water to approximately 75 mL, add 1 mL of hydrochloric acid solution and 2 mL of barium
chloride solution. Use water to dilute to the scale and shake it well. If the white turbidity
generated is deeper than the standard turbidity solution, then, it does not comply with the
indicator requirements specified in this document, otherwise, it complies with the indicator
requirements specified in this document.
The standard turbidity solution is to pipette (Category I and Category II Type I: 0.50 mL;
Category II Type II and Category III: 1.00 mL) sulfate standard solution, transfer it into a 100
mL colorimetric tube, add water to approximately 75 mL, and handle it at the same time in the
same way as the test solution of the same volume.
7.8 Determination of Carbonate Content
7.8.1.1 Principle
Take methyl orange as the indicator solution and use salt standard titration solution for titration.
7.8.1.2 Reagents or materials
7.8.1.2.1 Hydrochloric acid standard titration solution: c(HCl) 0.1 mol/L.
7.8.1.2.2 Hydrochloric acid standard titration solution: c(HCl) 0.5 mol/L.
7.8.1.2.3 Methyl orange indicator solution: 1 g/L.
7.8.1.3 Test steps
Use a pipette to transfer 50 mL or 5 mL (Category III) (V2) of test solution A (see 7.6.1.4.1),
place it in a 250 mL conical flask, and add 3 drops of methyl orange indicator solution. Use
c(HCl) 0.1 mol/L or c(HCl) 0.5 mol/L hydrochloric acid standard titration solution to titrate
it, until the solution turns orange.
7.8.1.4 Test data processing
The carbonate content, which is calculated as the mass fraction w6 of carbonate (CO3), shall be
calculated in accordance with Formula (6):
Where,
V---the volume of the hydrochloric acid standard titration solution consumed during titration,
expressed in (mL);
c---the accurate value of the concentration of hydrochloric acid standard titration solution,
expressed in (mol/L);
M---the numerical value of the molar mass of carbonate, expressed in (g/mol) [M(1/2 CO3) =
29.99];
m---the mass of the sample contained in test solution A (see 7.6.1.4.1) in 7.6.1.4.1, expressed
in (g);
V2---the volume of test solution A (see 7.6.1.4.1) transferred in 7.8.1.3, expressed in (mL);
V1---the volume of test solution A (see 7.6.1.4.1) in 7.6.1.4.1, expressed in (mL).
Take the arithmetic mean of parallel determination results as the determination result. The
absolute difference between two parallel determination results shall not be greater than 0.002%
for Category I and Category II products, and not greater than 0.02% for Category III products.
7.9 Determination of Ammonium Salt Content
7.9.2 Visual colorimetric method
7.9.2.1 Principle
In an alkaline solution, free ammonia or combined ammonium reacts with Nessler’s reagent
and generates a light yellow to brown colloidal compound. When the ammonium content is
relatively high, the product is a reddish-brown precipitate. When the ammonium content is
relatively low, then, a stable suspension is formed, which can be used for the visual colorimetric
determination of ammonium salt. Its main reaction formula is as follows:
7.9.2.2 Reagents or materials
7.9.2.2.1 Sodium hydroxide solution: 320 g/L.
7.9.2.2.2 Nessler’s reagent.
7.9.2.2.3 Ammonium standard solution: 1 mL of solution contains 0.1 mg of ammonium (NH4).
Use a pipette to transfer 10 mL of the ammonium standard solution prepared in accordance with
HG/T 3696.2, place it in a 100 mL volumetric flask, use water to dilute to the scale and shake
it well.
7.9.2.3 Test steps
Use a pipette to transfer 5 mL of test solution A (see 7.6.1.4.1) into a 100 mL colorimetric tube,
add water to approximately 75 mL, add 3 mL of sodium hydroxide solution and 2 mL of
Nessler’s reagent. Use water to dilute to the scale and shake it well. If the generated color is
deeper than the standard colorimetric solution, then, it does not comply with the indicator
requirements specified in this document, otherwise, it complies with the indicator requirements
specified in this document.
The standard colorimetric solution is to pipette ammonium standard solution [2.00 mL
(Category I) and 7.00 mL (Category II Type I)], transfer into a 100 mL colorimetric tube, add
water to approximately 75 mL, and handle it at the same time in the same way as the test
solution of the same volume.
7.10 Determination of Moisture Absorption Rate
7.10.1 Principle
Place the sample after the moisture content determination in a desiccator containing a saturated
potassium nitrate solution. At a certain temperature, place it for a certain period of time, then,
examine the moisture absorption of the sample.
7.10.2 Reagents or materials
Saturated potassium nitrate solution.
7.10.3 Instruments and equipment
Desiccator: with a diameter of 140 mm. The bottom layer contains 100 mL of saturated
potassium nitrate solution.
7.10.4 Test steps
Place the sample that has been dried to a constant mass in 7.4, together with the weighing bottle,
in a desiccator, remove the cap of the weighing bottle, and properly cover the desiccator. Place
it in an environment of 20 C 2 C for 6 hours, take out the weighing bottle and the cap, use
filter paper to dry the surface moisture, and weigh it.
7.10.5 Test data processing
The moisture absorption rate, which is calculated as the mass fraction w8, shall be calculated in
accordance with Formula (8):
Where,
m---the mass of the sample that has been dried to a constant mass in 7.4, expressed in (g);
m1---the mass of the sample after absorbing moisture, expressed in (g).
Take the arithmetic mean of two parallel determination results as the determination result. The
absolute difference of parallel determination results shall not be greater than 0.05%.
7.11 Determination of Looseness
7.11.1 Method summary
Freely drop bagged samples that have been stacked for a certain period of time onto a hard
surface from a height of 1 m. After sieving, weigh the mass of the sample left on the sieve.
7.11.2 Instruments
7.11.2.1 Test sieve: 950 mm long, 600 mm wide, with a wooden frame about 120 mm high, and
the mesh size is 4.75 mm.
7.11.2.2 Stopwatch.
7.11.2.3 Platform scale: 10 kg, with a division value of 0.1 kg.
7.11.3 Analysis steps
magnesium (Mg), barium (Ba), zinc (Zn), manganese (Mn), copper (Cu), cadmium (Cd),
chromium (Cr) and lead (Pb), 10 g each. Use a pipette to respectively transfer 10 mL of iron
(Fe), calcium (Ca), magnesium (Mg), barium (Ba), zinc (Zn), manganese (Mn), copper (Cu),
cadmium (Cd), chromium (Cr) and lead (Pb) standard solutions, place them in 100 mL
volumetric flasks, use water to dilute to the scale and shake them well.
7.12.3 Instruments and equipment
Inductively coupled plasma optical emission spectrometer (ICP-OES): determine 1 mg/L or 10
mg/L multi-element mixed standard solution and repeat the determination 10 times with an
RSD 0.5%. See Appendix A for the commonly used ICP-OES spectral lines and detection
limits of each determined ion.
7.12.4 Test steps
7.12.4.1 Preparation of test solution
Weigh-take about 10 g of sample, accurate to 0.01 g. Place it in a 250 mL beaker, add about
150 mL of water, heat to boiling to completely dissolve the specimen, then, cool it to room
temperature. Transfer all into a 250 mL (V1) volumetric flask, use water to dilute to the scale
and shake it well.
7.12.4.2 Test
Use a pipette to respectively take 5 portions of 20 mL (V2) of test solution and place them in
five 100 mL volumetric flasks. Respectively add 5 mL of nitric acid solution to each, then,
respectively add 0.0 mL, 1.00 mL, 2.00 mL, 3.00 mL and 4.00 mL of the metal ion standard
mixed solution, use water to dilute to the scale and shake them well.
Turn on the inductively coupled plasma optical emission spectrometer (ICP-OES), and after the
operation is stable, under the selected optimized conditions, respectively determine the
emission spectrum intensity of different masses of each metal ion. Take the mass value A of the
determined metal ion as the x-coordinate, and the corresponding emission spectrum intensity I
as the y-coordinate to draw a working curve. Intersect the reverse extension line of the curve
with the x-coordinate, and the distance between the intersection point and the origin is the mass
of the determined ion (see Figure 1). Thus, the content of each ion can be obtained through
calculation.
When there is an update of key production processes;
When there are changes in the main raw materials;
When production is suspended and resumed;
When there are relatively significant differences from the previous type
inspection;
When it is stipulated in the contract.
b) In the requirements, potassium nitrate, moisture, water-insoluble matter, chloride,
sulfate, carbonate, ammonium salt content and moisture absorption rate are exit-
factory inspection items, which shall be inspected batch by batch.
8.2 Industrial potassium nitrate of the same specifications and continuously produced or by the
same team using the same materials and basically the same production conditions is considered
as one batch. Each batch of products shall not exceed 100 t.
8.3 In accordance with the stipulations of GB/T 6678, determine the number of sampling units.
During sampling, insert the sampler from the top of the packaging bag to 3/4 depth of the
material layer for sampling. Evenly mix the collected samples and cut them into quarters to
about 800 g, respectively put them into two dry, clean jars or plastic bags, and seal. Attach a
label to the jars or bags, indicating manufacturer’s name, product name, type, grade, batch No.,
sampling date and sampler’s name. One is used as laboratory sample, and the other is kept for
future reference. The retention time is determined by the manufacturer based on actual demands.
8.4 If any indicator in the inspection results does not comply with the requirements of this
document, sampling shall be conducted from twice the amount of packaging for a re-inspection.
When even one indicator in the re-inspection results does not comply with the requirements of
this document, then, the entire batch of products shall be deemed disqualified.
8.5 Adopt the rounding-off comparison method specified in GB/T 8170 to determine whether
the inspection results comply with the document.
9 Marking and Labeling
9.1 The packaging bags of potassium nitrate for industrial use must have solid and clear
markings, including manufacturer’s name and address, product name, category, type, net
content, batch No. or production date, serial No. of this document, as well as the “Oxidizing
Substance” mark stipulated in Chapter 3 of GB 190-2009, and the “Avoid Sun Exposure” and
“Keep Dry” marks stipulated in Chapter 2 of GB/T 191-2008.
9.2 Each batch of potassium nitrate for industrial use exiting the factory shall be accompanied
by a quality certificate, including manufacturer’s name and address, product name, category,
type, net content, batch No. or production date, and serial No. of this document.
......
GB 1918-2011
Potassium nitrate for industrial use
ICS 71.060.50
G12
National Standards of People's Republic of China
Replacing GB/T 1918-1998
Industrial kno
Issued on. 2011-12-05
2012-08-01 implementation
Administration of Quality Supervision, Inspection and Quarantine of People's Republic of China
Standardization Administration of China released
Foreword
Chapter 7 and Chapter 8 of the contents of this standard is mandatory, the rest are recommended.
This standard was drafted in accordance with GB/T 1.1-2009 given rules.
The reference to the revised standard Russian Standard ГOCT19790. 1974 (1995) "Industrial Potassium saltpeter (potassium nitrate)" (Russian) in
Class B.
This standard replaces GB/T 1918-1998 "industrial potassium nitrate."
This standard and GB/T 1918-1998 The main technical difference.
--- Carbonate content additional indicators and test methods (1998 version 3.2, this version 4.2);
--- The formula subtracts the content of potassium nitrate and potassium carbonate content corresponding to the value (1998 version 4.1.4, this edition
5.4.5);
--- Determination of chloride content and limited use of mercury Method nephelometry (1998 version 4.3, this version 5.8).
The standard proposed by China Petroleum and Chemical Industry Association.
This standard by the National Standardization Technical Committee chemical inorganic chemicals Club (SAC/TC63/SC1) centralized.
This standard was drafted. CNOOC Tianjin Chemical Research & Design Institute, Zhejiang General Assembly Chemical Co., Ltd., Jiangxi Yichun City Tengda Chemical Co.
Ltd., Sichuan dangerous chemicals quality supervision, inspection, Hunan Liuyang City, the US Austrian Chemical Co., Ltd. Xingping City, Shaanxi Province Yi-sheng Chemical
limited liability company.
The main drafters of this standard. Li Xiaofeng, Yu Ronghua, Zhaojia Chun, Zhang Jingjuan, Zhao Chen, Cai Bo, Cai Binghua.
This standard replaces the standards previously issued as follows.
--- GB 1918-1980, GB 1918-1986, GB/T 1918-1998.
Industrial kno
Warning. Potassium nitrate is a strong oxidant, contact with organic matter, under certain conditions can cause a fire explosion and release irritating
Toxic gases, with carbon or sulfur co heat, and combustion can emit light. In the production, storage and use of the process should pay attention to safety.
1 Scope
This standard specifies the industrial potassium nitrate requirements, test methods, inspection rules and signs, packaging, transportation, storage, and security.
This standard applies primarily as a black powder, fuse, optical glass, ammonia catalysts, metal heat treatment, and pharmaceutical intermediates, and other raw materials enamel
Industrial potassium nitrate.
2 Normative references
The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein
Member. For undated references, the latest edition (including any amendments) applies to this document.
GB 190-2009 dangerous goods packaging logo
GB/T 191-2008 Packaging - Pictorial signs
GB/T 685-1993 Chemical Reagent formaldehyde solution
General Method GB/T 3049-2006 industrial chemicals determination of iron content 1,10-phenanthroline spectrophotometry
GB/T 3051-2000 Inorganic chemical products for the general method of determination of chloride content of mercury Method
GB/T 6678 General Principles for Sampling Chemical Products
Laboratory use specifications and test methods GB/T 6682-2008 Analysis
GB/T 8170 repair value expressed about the rules and limit values and judgment
GB/T 8946-1998 plastic bags
GB/T 23945-2009 General method for inorganic chemical products, determination of chloride content Visible turbidimetric method
Preparation of standard titration solution of HG/T 3696.1 inorganic chemical products, chemical analysis
Preparation of HG/T 3696.2 inorganic chemical products, chemical analysis of impurity standard solution
Preparations of HG/T 3696.3 inorganic chemical products, chemical analysis
3 formula, relative molecular mass
Molecular formula. KNO3
Molecular weight. 101.10 (according to 2007 international relative atomic mass)
4 Requirements
4.1 Appearance. white crystal or spherical particles.
4.2 Potassium nitrate industry should meet the requirements of Table 1.
Table 1 Requirements
project
index
Premium grade First grade Qualified
Potassium nitrate (KNO3), w /% ≥ 99.7 99.4 99.0
Water, w /% ≤ 0.10 0.20 0.30
Carbonate (K2CO3 to count), w /% ≤ 0.01 0.01 -
Sulfate (SO4 dollars), w /% ≤ 0.005 0.01 -
Chloride (Cl dollars), w /% ≤ 0.01 0.02 0.10
Water-insoluble, w /% ≤ 0.01 0.02 0.05
Absorption rate, w /% ≤ 0.25 0.30 -
Iron (Fe), w /% ≤ 0.003 - -
Salt content according to user requirements, according to the method specified in this standard were measured.
5 Test methods
5.1 Safety Tips
Reagents and samples of the test method used in toxic or corrosive shall be established as careful operation splashed on the skin
That is rinsed with water, severe cases should be treated immediately. Volatile organic reagents with most impact on human health and flammable, when operating through
Fume hood, to avoid contact with open flame.
5.2 General Provisions
The standard reagents and water, did not indicate when additional requirements are specified analytical reagent refers to 6682-2008 and GB/T 's
Three water. Standard titration solution used in the tests, the impurity standard solution, preparations and products, in the absence of other provisions indicate, according to
HG/T 3696.1, the provisions prepared HG/T 3696.2 and HG/T 3696.3 of.
5.3 appearance of discrimination
Under natural light conditions, with visual discrimination method.
5.4 Determination of potassium nitrate content
Safety Tips. this operation when heating is prohibited the use of fire.
5.4.1 Method summary
In neutral medium, potassium and sodium tetraphenylborate react to produce potassium tetraphenylborate precipitate. If ammonium ions, may be added to the formaldehyde solution
It was to eliminate the interference of ammonium ions. According to the quality of the resulting potassium tetrophenlborate determine nitrate content.
5.4.2 Reagents
5.4.2.1 ethanol.
5.4.2.2 formaldehyde (prepared before, using the filtering by the provisions of Appendix A).
5.4.2.3 acetic acid. 1100.
5.4.2.4 sodium hydroxide solution. 4g/L.
5.4.2.5 ethanol solution of sodium tetraphenylborate. 34g/L;
Weigh 3.4g sodium tetraphenylborate dissolved in 100mL anhydrous ethanol, with the time is now equipped with a pre-filter.
5.4.2.6 Tetraphenylboron ethanol saturated solution of potassium.
Potassium Tetraphenylborate Weigh 1g ~ 2g of the test after the precipitation, plus ethanol 50mL, 950mL of water, shake well before use and filtered.
5.4.2.7 methyl orange indicator solution. 0.4g/L.
5.4.2.8 phenolphthalein indicator solution. 10g/L.
5.4.3 Instruments
5.4.3.1 electric oven. the temperature can be controlled at 120 ℃ ± 2 ℃.
5.4.3.2 sintered glass crucible. filter plate pore size of 5μm ~ 15μm.
5.4.4 Analysis of step
Weigh about 1g ~ 1.2g sample, accurate to 0.0002g. Placed in 100mL beaker, dissolved in water, the solution was transferred to a 500mL capacity
Volumetric flask, dilute to the mark, shake. Dry filter, discard before going 25mL filtrate pipette Pipette 25mL solution was placed in 150mL
Beaker, add 20mL water, 2 drops of methyl orange indicator solution, the solution was adjusted with acetic acid solution just red; ammonium salt as raw materials for the production of nitric acid
Potassium, add 1 drop to 2 drops of phenolphthalein indicator solution, 2mL formaldehyde, sodium hydroxide solution and the solution was adjusted to reddish. The solution was heated with a water bath
To 45 deg.] C (reddish solution was maintained) (if needed precipitate was filtered and washed), was added dropwise with stirring under 8mL ethanol solution of sodium tetraphenylborate
Solution (dropwise addition time is about 5min), stirring was continued for 1min. After standing 30min, with a pre-dried at 120 ℃ ± 2 ℃ in electric oven
Dry to a constant mass of glass sand filtration crucible. With 20mL of ethanol saturated potassium tetraphenylborate solution was transferred precipitated with 15mL Tetraphenylboron potassium acetate
Alcohol saturated solution was washed three to four times precipitation (each should be drained), washed with 2mL ethanol along the wall of the crucible once, drained. At 120 ℃ ±
2 ℃ electric oven to bake in a constant quality.
5.4.5 Calculation Results
Nitrate content of potassium nitrate (KNO3) mass fraction w1 meter, according to equation (1).
w1 = m1 × 0.2822
m × 25500
× 100% -1.463w3 (1)
Where.
Value m1 --- potassium tetraphenylborate precipitate mass, in grams (g);
Numerical m --- sample mass, in grams (g);
w3 --- 5.6 measured by potassium carbonate (K2CO3) mass fraction, expressed as a percentage;
.2822 --- Tetraphenylboron potassium nitrate in terms of the coefficients;
1.463 --- potassium carbonate (K2CO3) is converted to nitrate coefficients.
Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.3%.
5.5 Determination of Moisture
5.5.1 Method summary
At a predetermined temperature, a predetermined amount of the sample was dried to constant mass measurement sample to reduce the quality of the water is determined.
5.5.2 instruments and equipment
5.5.2.1 electric oven. the temperature can be controlled at 105 ℃ ~ 110 ℃;
5.5.2.2 weighing bottle. φ50mm × 30mm.
5.5.3 Analysis of step
It weighs about 10g sample, accurate to 0.0002g. Add to advance electric oven 105 ℃ ~ 110 ℃ dried to quality
Constant weighing bottle and placed electric oven 105 ℃ ~ 110 ℃ dried to constant mass.
5.5.4 Calculation Results
Moisture content in w2 dollars, according to equation (2).
w2 = m-m1m × 100%
(2)
Where.
Value m1 --- quality of the sample after drying, in grams (g);
Numerical m --- sample mass, in grams (g).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.01%.
5.6 Determination of carbonate content
5.6.1 Method summary
The sample is dissolved in water, add methyl orange indicator solution, titration with hydrochloric acid solution to the sample solution turned orange.
5.6.2 Reagents
5.6.2.1 hydrochloric acid standard titration solution. c (HCl) ≈0.1mol/L.
5.6.2.2 methyl orange indicator solution. 0.4g/L.
5.6.3 Analysis of step
Weigh about 5g sample to the nearest 0.01g. Placed in 250mL conical flask, add 50mL dissolved carbon dioxide-free water, add 3 drops
Methyl orange indicator solution, titration with hydrochloric acid standard titration solution until the solution turned orange.
5.6.4 Calculation Results
Carbonate content with potassium carbonate (K2CO3) mass fraction w3 meter, according to equation (3) Calculated.
w3 = 10
-3VcM
m × 100%
(3)
Where.
Numerical V --- hydrochloric acid standard titration solution volume of titration solution consumed in milliliters (mL);
Accurate c --- hydrochloric acid standard titration solution concentration value in units of moles per liter (mol/L);
Numerical m --- sample mass, in grams (g);
M --- potassium carbonate (12K2CO3
) Molar mass values, in units of grams per mole (g/mol) (M = 69.10).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.002%.
5.7 Determination of sulphate content
5.7.1 Method summary
In acidic medium, sulfate ions and barium ions form insoluble barium sulfate, when the low sulfate ion content, within a certain time
Barium sulfate suspension in the solution, the solution was turbid turbidimetry Kraft visual.
5.7.2 Reagents
5.7.2.1 hydrochloric acid solution. 14.
5.7.2.2 barium chloride solution. 100g/L.
5.7.2.3 sulfate standard solution. 1mL solution containing sulphate (SO4) 0.1mg. Pipette Pipette 10mL press HG/T 3696.2
Sulfate standard solution prepared, placed in 100mL flask, diluted with water to the mark.
5.7.3 Analysis of step
5.7.3.1 Preparation of test solution A
Weigh about 5g sample to the nearest 0.01g. Placed in 100mL beaker, add water to dissolve 50mL, quantitative filter paper in
100mL flask, sufficiently washed filter paper, diluted with water to the mark. This solution as the test solution A, Kraft and visual inspection
Determination of chloride content.
5.7.3.2 Determination
Pipette Pipette the appropriate amount of test solution A (Excellence in goods. 20mL; First grade. 10mL), placed in 50mL colorimetric tube, add water to about
40mL, add 1mL hydrochloric acid solution, 1mL barium chloride solution, diluted with water to the mark. Place 5min, the turbidity was not deeper than the standard
Turbidimetric solution.
Turbidity standard solution preparation. pipette Pipette 0.5mL sulfate standard solution, the test solution simultaneously with the same treatment.
5.8 Determination of chloride content
5.8.1 Mercury Method (Arbitration Act)
5.8.1.1 Method summary
With GB/T 3051-2000 Chapter 2.
5.8.1.2 Reagents
5.8.1.2.1 urea.
5.8.1.2.2 with GB/T 3051-2000 Chapter 4.
5.8.1.3 instruments and equipment
With GB/T 3051-2000 Chapter 5.
5.8.1.4 analysis step
It weighs about 25g sample to the nearest 0.01g. Placed in 250mL conical flask, add 80mL water, 3g of urea, dissolved by heating. Micro
Nitric acid solution was added dropwise to boiling under no fine bubbles, cooled to room temperature. Add 3 drops of bromophenol blue indicator solution, the solution was adjusted with sodium hydroxide solution
Blue, then dropping to just solution of nitric acid yellow, then 5 drops of excess. Join 1mL diphenylcarbazone hydrazine indicator solution, the use of micro-burette
With 0.05mol/L nitrate mercury standard titration solution titration solution from yellow to purple.
Blank test. Take 80mL water placed in 250mL conical flask, while the same treatment plus 3g of urea from the beginning of the sample.
5.8.1.5 Calculation Results
Chloride content quality chlorine (Cl) scores w4 meter, according to equation (4) Calculated.
w4 = 10
-3 (V-V0) cM
m × 100%
(4)
Where.
Numerical V --- nitrate mercury standard titration solution volume of titration solution consumed in milliliters (mL);
Value V0 --- nitrate mercury standard titration solution volume of solution consumed in the blank titration, in milliliters (mL);
Accurate c --- mercuric nitrate standard titration solution concentration value in units of moles per liter (mol/L);
Numerical m --- sample mass, in grams (g);
--- The M value chlorine (Cl) molar mass of the units of grams per mole (g/mol) (M = 35.45).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference between the high-class product and first-class goods is not more than
0.001%, qualified not more than 0.01%.
5.8.2 Visible turbidimetric method
5.8.2.1 Method summary
With GB/T 23945-2009 Chapter 3.
5.8.2.2 Reagents
With GB/T 23945-2009 Chapter 6.
5.8.2.3 analysis step
Pipette Pipette the appropriate amount of test solution A (5.7.3.1) (Excellence in goods. 10.0mL; First grade. 5.00mL; Qualified. 1.00mL),
Placed in 50mL colorimetric tube, add water to about 40mL, add 1mL 1mL solution of nitric acid and silver nitrate solution, dilute to the mark, shake,
Stand 10min. The resulting white turbidity is not deeper than the standard turbidity solution.
Standard turbidity solution is a standard solution Pipette 5.00mL chloride [1mL chlorine (Cl) 0.010mg], and at the same time the same test solution
deal with.
5.9 Determination of water-insoluble content
5.9.1 Method summary
Weigh a certain amount of sample was dissolved in water, filtered, and the residue dried under certain temperature conditions, after weighing, to determine the water-insoluble content.
5.9.2 Reagents
Diphenylamine - sulfuric acid indicator solution. 10g/L.
5.9.3 instruments and equipment
5.9.3.1 electric oven. the temperature can be controlled at 105 ℃ ~ 110 ℃.
5.9.3.2 sintered glass crucible. filter plate pore size of 5μm ~ 15μm.
5.9.4 Analysis of step
It weighs about 25g sample to the nearest 0.01g. Placed in 250mL beaker, add 100mL water dissolved by heating and boiling, has been used previously
At 105 ℃ ~ 110 ℃ dried to a constant mass of glass sand filter crucible. The filtrate was washed with water until free of nitrate ions (with diphenyl
Amine - sulfuric acid test is not significant indicator solution blue), sand glass crucible together with insolubles were placed in the electric oven at 105 ℃ ~ 110 ℃ Article
Drying the pieces to a constant quality.
5.9.5 Calculation Results
The mass fraction of water insoluble to w5 dollars, according to equation (5) Calculated.
w5 = m1m × 100%
(5)
Where.
Value m1 --- Water insoluble mass in grams (g);
Numerical m --- sample mass, in grams (g).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.003%.
Determination of moisture absorption rate of 5.10
5.10.1 Method summary
The sample is placed after the determination of water containing a saturated potassium nitrate solution, dryer, placed at a certain temperature after 6h, weighed.
5.10.2 Instruments
Dryer. Diameter φ140mm, the bottom filled with 100mL of saturated potassium nitrate solution.
5.10.3 analysis step
5.5 The sample is dried to constant mass after weighing bottle is placed along with the dryer, remove the weighing bottle, the dryer cover. in
20 ℃ ± 2 ℃ temperature placed under 6h, remove the weighing bottle and cap, wipe the surface of water with filter paper and weighed.
5.10.4 Calculation Results
The mass fraction of moisture absorption to w6 dollars, according to equation (6) Calculated.
w6 = m1-mm × 100%
(6)
Where.
Mass m1 --- sample after absorbing moisture in grams (g);
5.5 m --- Press dried to a constant value the quality of the sample mass, in grams (g).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.05%.
5.11 Determination of iron content
5.11.1 Method summary
According to GB/T 3049-2006 of Chapter 3.
5.11.2 Reagent
According to GB/T 3049-2006 of Chapter 4.
5.11.3 Instruments
According to GB/T 3049-2006 of Chapter 5.
5.11.4 analysis step
5.11.4.1 draw the curve
According to the provisions of GB/T 3049-2006 6.3 using 4cm absorption cell drawing working curve.
5.11.4.2 Determination
Weigh about 2g samples, accurate to 0.01g. Placed in 100mL beaker, was added 20mL of water to dissolve, the pH was adjusted with hydrochloric acid (13)
About 2 (with a precision pH test paper). The entire solution was transferred to a 100mL volumetric flask, add water to about 60mL. The following press
The provisions of GB/T 3049-2006 6.4, from the "test solution quantitatively transferred to 100mL volumetric flask," began to operate. Simultaneously
Blank test.
Blank test in the preparation of the test solution at the same time, but without addition of the sample, the type and quantity of the test solution and other operations and the addition of reagents
the same.
5.11.5 Calculation Results
Iron content of iron (Fe) mass fraction w7 meter, according to equation (7) Calculated.
w7 =
(M1-m0) × 10-3
m × 100%
(7)
Where.
m1 --- Richard from the working curve test numerical solution of iron mass, in milligrams (mg);
m0 --- from the working curve Richard blank test numerical solution of iron mass, in milligrams (mg);
Numerical m --- sample mass, in grams (g).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.0005%.
Determination of salt content of 5.12
5.12.1 Method summary
Ammonium salt reaction with formaldehyde generated in a neutral medium, hexamethylenetetramine and ammonium salt of the acid equivalent, using phenolphthalein as indicator hydroxide
Sodium standard titration solution titration.
5.12.2 Reagent
5.12.2.1 hydrochloric acid solution. 120.
5.12.2.2 formaldehyde solution. 12;
Should phenolphthalein indicator solution before use, with 0.1mol/L sodium hydroxide standard titration solution titration to pale pink.
5.12.2.3 sodium hydroxide standard titration solution. c (NaOH) ≈0.1mol/L.
5.12.2.4 phenolphthalein indicator solution. 10g/L.
5.12.3 analysis step
It weighs about 10g sample to the nearest 0.01g. Placed in 250mL Erlenmeyer flask, dissolved in 80mL of water, adding 1 to 2 drops of phenolphthalein indicator
Solution, titrated with sodium hydroxide solution or hydrochloric acid standard titration standard solution was adjusted to neutral. Add 10mL formaldehyde solution, shake for 5min.
Standard titration with sodium hydroxide solution titration solution to pale pink, holding 30s does not fade, is the end. While doing the blank test.
Blank test in the preparation of the test solution at the same time, but without addition of the sample, the type and quantity of the test solution and other operations and the addition of reagents
the same.
5.12.4 Calculation Results
Ammonium salt ammonium (NH4) w8 mass fraction meter, according to equation (8) Calculated.
w8 = 10
-3 (V-V0) cM
m × 100%
(8)
Where.
Accurate c --- sodium hydroxide standard titration solution concentration value in units of moles per liter (mol/L);
Numerical solution of sodium hydroxide standard titration volume V --- titration test solution consumed in milliliters (mL);
Numerical solution of sodium hydroxide standard titration volume V0 --- titrate blank solution consumed in milliliters (mL);
Numerical m --- sample mass, in grams (g);
--- The M values of molar mass ammonium (NH4), in units of grams per mole (g/mol) (M = 18.04).
Take the arithmetic mean of the parallel determination results of the measurement results, the results of two parallel determination of the absolute difference is not more than 0.005%.
6 Inspection rules
6.1 All items specified in this standard are factory inspection items should be tested batches.
6.2 with the same material, the same basic production conditions, continuous production of industrial production or the same team as potassium nitrate, each batch of products is not
To 60t.
6.3 determine the sampling units according to GB/T 6678 provisions. The sampler from the center of the bag vertically into the material layer to a depth of 3/4 of the harvest
kind. The sample was taken out of the mix, take out less than 500g. The sampled goods packed in two clean, dry container, sealed and paste
Labels, indicating manufacturer name, product name, grade, batch number, date of sampling and sampling by name. Made for a laboratory sample, and a second copy
For future reference, saving time is determined by the manufacturer as required.
6.4 If the test results do not meet the requirements of this standard indicators, sampling should retest again from twice the amount of packaging, even if re-inspection results
There are an indicator does not meet the requirements of this standard, then the entire batch of products falling grades or failed.
6.5 numerical GB/T 8170 provisions of rounding value comparison test determines whether the results meet the standards.
7 signs, packaging, transportation and storage
7.1 Industrial potassium nitrate should be firmly on the bag clearly labeled, including. manufacturer's name and address, product name, grade, net content, batch
Number or date of manufacture, and serial number of the standard set forth in GB 190-2009 "oxidizing substance" signs and the GB stipulated 191-2008
"Afraid of the rain" signs.
7.2 each batch of industrial potassium nitrate should be accompanied by a certificate of quality. They include. manufacturer's name and address, product name, grade, containing a net
Proof of the amount, lot number or production date, product quality and compliance with this standard and this standard number.
7.3 Industrial potassium nitrate film bag lined with polyethylene plastic woven bag, polyethylene film bag thickness not less than 0.04mm, outsourcing
Performance and test methods of packaging material shall comply with GB/T 8946's. When packaging, the inner bag air drain, with Vinylon rope or quality
Quite artificial cuff rope; outer bag should be firmly sewn. Net weight 50kg or agreed with the user.
7.4 Industrial potassium nitrate in......
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