1
/
of
12
www.ChineseStandard.us -- Field Test Asia Pte. Ltd.
GB/T 30835-2014 English PDF (GB/T30835-2014)
GB/T 30835-2014 English PDF (GB/T30835-2014)
Regular price
$430.00
Regular price
Sale price
$430.00
Unit price
/
per
Shipping calculated at checkout.
Couldn't load pickup availability
GB/T 30835-2014: Lithium iron phosphate-carbon composite cathode materials for lithium ion battery
Delivery: 9 seconds. Download (& Email) true-PDF + Invoice.
Get Quotation: Click GB/T 30835-2014 (Self-service in 1-minute)
Historical versions (Master-website): GB/T 30835-2014
Preview True-PDF (Reload/Scroll-down if blank)
GB/T 30835-2014
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 29.050
Q 53
Lithium iron phosphate-carbon composite cathode materials
for lithium ion battery
ISSUED ON: JUNE 24, 2014
IMPLEMENTED ON: APRIL 01, 2015
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 5
4 Classification and codes ... 5
5 Technical requirements ... 6
6 Test methods ... 7
7 Inspection rules ... 9
8 Packaging, marks ... 11
9 Storage and transportation ... 11
Annex A (normative) Method for determination of lithium content (excluding carbon
content) ... 13
Annex B (normative) Method for determination of iron content (excluding carbon
content) ... 17
Annex C (normative) Method for determination of phosphorus content (excluding
carbon content) ... 21
Annex D (informative) Method for determination of crystal structure ... 26
Annex E (normative) Method for determination of iron ion dissolution rate ... 29
Annex F (normative) Method for determination of first coulombic efficiency, first
reversible specific capacity, rate performance ... 33
Annex G (normative) Method for determination of conductivity ... 38
Lithium iron phosphate-carbon composite cathode materials
for lithium ion battery
1 Scope
This Standard specifies the terms and definitions, classification and codes, technical
requirements, test methods, inspection rules and packaging, marking, storage and
transportation for lithium iron phosphate-carbon composite cathode materials for
lithium ion battery.
This Standard applies to lithium iron phosphate-carbon composite cathode materials for
lithium ion battery.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 191, Packaging and storage marks
GB/T 5162, Metallic powders -- Determination of tap density
GB/T 6283, Chemical products -- Determination of water Karl-Fischer method
(general method)
GB/T 6388, Transport package shipping mark
GB/T 6682, Water for analytical laboratory use -- Specification and test methods
GB/T 9724, Chemical reagent -- General rule for the determination of pH
GB/T 12805, Laboratory glassware -- Burettes
GB/T 13732, General rules for sampling inspection of bulk materials with uniform
size
GB/T 19077.1, Particle size analysis -- Laser diffraction methods -- Part 1: General
principles
GB/T 19587, Determination of the specific surface area of solids by gas adsorption
using the BET method
GB/T 20123, Steel and iron -- Determination of total carbon and sulfur content
Infrared absorption method after combustion in an induction furnace (routine
method)
GB/T 24533-2009, Graphite negative electrode materials for lithium ion battery
JCPDS (01-077-0179), Lithium iron phosphate X-ray powder diffraction standard
pattern
IEC 62321, Electrotechnical products - Determination of levels of six regulated
substances (lead, mercury, cadmium, hexavalent chromium, polybrominated
biphenyls, polybrominated diphenyl ethers)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 lithium iron phosphate-carbon composite cathode materials
Lithium-ion battery cathode material composed of lithium iron phosphate and carbon
with an olivine structure. Lithium iron phosphate belongs to the orthorhombic crystal
system. It has a one-dimensional lithium embedded channel. Lithium ions can be
reversibly deintercalated within the crystal lattice. The theoretical specific capacity of
the material is 170 mA·h/g.
NOTE: LFP@C mentioned in this Standard all represents lithium iron phosphate-carbon composite
cathode materials.
4 Classification and codes
4.1 Product classification
Lithium iron phosphate-carbon composite cathode materials are divided into energy
type and power type according to charge and discharge characteristics and usage
requirements, represented by LFP@C-E and LFP@C-P respectively. LFP represents
lithium iron phosphate, @ represents the composite of two materials, C represents
carbon, E represents energy type, and P represents power type:
- Energy type lithium iron phosphate-carbon composite cathode materials (LFP@C-
E) are divided into three categories, represented by LFP@C-E-Ⅰ, LFP@CE-Ⅱ,
and LFP@C-E-Ⅲ. The specific performance requirements are detailed in Table
2;
- Power type lithium iron phosphate-carbon composite cathode materials (LFP@C-
P) are divided into three categories, represented by LFP@C-P-Ⅰ, LFP@CP-Ⅱ, and
LFP@C-P-Ⅲ. The specific performance requirements are detailed in Table 2.
6.17 Conductivity
Measure according to the measurement method specified in Annex G.
6.18 Restricted substance content
The measurement is carried out according to the measurement method specified in IEC
62321.
7 Inspection rules
7.1 Sampling method
7.1.1 Sampling
7.1.1.1 Lithium iron phosphate-carbon composite cathode materials for bagged lithium-
ion batteries shall be sampled in accordance with GB/T 13732. Open the bag of lithium
iron phosphate-carbon composite cathode material to be collected in a dry environment.
Use a clean stainless steel sampling drill to insert into the bag along the axis. The
insertion depth shall not be less than 4/5 of the depth of the sampling bag. Samples are
taken within 20 mm around the central axis of the material in the bag.
7.1.1.2 In order to make the collected samples represent the quality of this batch of
products, all collected samples are combined. Place on a square film of sufficient
strength and appropriate size or firm, soft drying paper. Mix evenly by rolling
repeatedly (turn more than 15 times). The mixed sample shall not be less than 500 g.
Cut off two 250 g specimens, one for testing and one for backup.
7.1.2 Sample label
After the sample is placed in the PVC sample jar, a label is immediately attached to the
outer wall. The label includes the following:
a) Sample type and number;
b) Overall material batch number and quantity;
c) Sample size;
d) Sampling date;
e) Name of sampler.
7.1.3 Storage of samples
7.1.3.1 Samples shall be sealed and stored in anti-breakage bags, rain-proof, moisture-
proof and other environments.
7.1.3.2 The effective storage period of spare samples is 12 months.
7.2 Inspection
7.2.1 Exit-factory inspection
Inspect the particle size, carbon content, moisture content, BET specific surface area,
tap density, electrochemical performance, iron ion dissolution amount, conductivity and
other indicators of each batch of samples. They can be shipped only after passing the
inspection.
7.2.2 Type inspection
All technical requirements specified in this Standard shall be inspected. Type inspection
is carried out when one of the following situations occurs:
a) When there are changes in raw material models, supplier manufacturers, etc.;
b) When there are changes in the production process;
c) When the production equipment has been shut down for more than half a year and
then starts production for the first time;
d) When customers have special requirements.
7.3 Acceptance rules
7.3.1 Products that meet all the technical indicators required by a certain category in
Table 2 are qualified products. If an indicator fails to meet the requirements of this
category, double samples shall be taken from the sampling bags of the same batch of
products to re-inspect the unqualified items. The re-inspection results shall be taken as
the final result. Products that do not fall into the product categories in Table 2 or have
special requirements must be determined through negotiation between the supplier and
the purchaser to determine whether they are qualified.
7.3.2 The inspection department of the manufacturer shall ensure that the products
shipped meet the requirements of this Standard. When each batch of products leaves
the factory, a product quality inspection report is sent to the recipient.
7.3.3 The consignee has the right to accept products in accordance with this Standard
and the right to reject products that do not meet the requirements of this Standard.
7.3.4 The consignee shall conduct acceptance inspection of the product within one
month after receiving the product. If there is any objection, a spare sample shall be used
for re-inspection. If there is still a dispute, it will be arbitrated by the superior quality
supervision department.
Annex A
(normative)
Method for determination of lithium content (excluding carbon content)
A.1 Scope of application
This appendix is applicable to the determination of lithium content (except carbon
content) in specimens by inductively coupled plasma optical emission spectrometry.
A.2 Method summary
The specimen is dissolved in hydrochloric acid. In hydrochloric acid medium,
according to the optimized working conditions of the instrument, use the working curve
method and the inductively coupled plasma emission spectrometer to measure the
lithium ion content.
A.3 Reagents and materials
Without special instructions, the water used in the tests in this Standard refers to water
that meets the requirements in GB/T 6682 for the grade three water. All reagents used
in the test are analytically pure.
A.3.1 Concentrated hydrochloric acid
ρ 1.19 g/mL.
A.3.2 Argon gas
The volume fraction is not less than 99.999%.
A.3.3 Lithium standard solution
The concentration is 1000 μg/mL. It is a national certified standard sample and can be
stored for 1 year.
A.3.4 Preparation of reserve standard solutions
Take 5.00 mL of lithium standard solution (see A.3.3) in a 100 mL volumetric flask.
Add 2.00 mL of concentrated hydrochloric acid (see A.3.1). Add water and set the
volume constant to the scale. Shake well. Prepare a stock standard solution with a
lithium ion concentration of 50.00 μg/mL.
A.3.5 Preparation of series of standard solutions
Accurately measure 0 mL, 1.00 mL, 2.00 mL, 5.00 mL, and 10.00 mL of lithium ion
reserve standard solutions (see A.3.4) and place them into five 100 mL volumetric flasks.
Add 2.00 mL of concentrated hydrochloric acid to each (see A.3.1). Add water and set
the volume constant to the scale. Shake well. Prepare standard sample blanks and a
series of standard solutions with lithium ion concentrations of 0 μg/mL, 0.50 μg/mL,
1.00 μg/mL, 2.50 μg/mL, and 5.00 μg/mL. The ion content in the solution to be tested
shall be within the range of the standard curve.
A.4 Instruments and equipment
A.4.1 Inductively coupled plasma emission spectrometer.
A.4.2 Microwave digestion apparatus (including sample tank) or digestion device with
equivalent performance.
A.4.3 Electronic balance (resolution: 0.0001 g).
A.5 Analysis steps
A.5.1 Number of measurements
Take two samples for parallel sample testing. Take the arithmetic mean.
A.5.2 Blank test
Do a blank test along with the specimen.
A.5.3 Standard curve
Linear correlation coefficient ≥0.9995.
A.5.4 Preparation of sample solution to be tested
Weigh 0.10 g ± 0.02 g (accurate to 0.0001 g) of specimen into a clean sample jar. Add
9.00 mL of concentrated hydrochloric acid (see A.3.1). Place in microwave digestion
apparatus (see A.4.2). After digestion is complete, cool to room temperature. Filter and
set the volume constant. Dilute the sample solution to a constant volume appropriately
(refer to the preparation method of the reserve standard solution for dilution). Ensure
that the lithium ion concentration in the sample solution to be tested is within the
standard curve.
A.5.5 Determination
After the instrument is running stably, in accordance with the conditions in Table A.1,
inject the standard sample blank and the series of standard solutions (see A.3.6) in
sequence for measurement. Draw a curve. Then measure the specimen blank and the
sample solution to be tested (see A.5.4) in the same way. Use blank subtraction to
correct the results.
Annex B
(normative)
Method for determination of iron content (excluding carbon content)
B.1 Scope of application
This appendix is applicable to the potassium dichromate standard solution titration
method for determining the total iron content (except carbon content) in the specimen.
B.2 Method summary
After the specimen is dissolved with perchloric acid, CuSO4-isatin is used as the
indicator, and tin dichloride and titanium trichloride are used to reduce the ferric iron
to divalent iron. Use sodium diphenylamine sulfonate as indicator and potassium
dichromate standard solution for titration test.
B.3 Reagents and materials
Without special instructions, the water used in this Standard test refers to grade three
water specified in GB/T 6682, and the reagents used in the test are all analytically pure.
B.3.1 Perchloric acid, ρ 1.76 g/mL
Guaranteed reagent.
B.3.2 Hydrochloric acid, 1:1
Dilute with hydrochloric acid (ρ 1.19 g/mL) and water at a volume ratio of 1:1.
B.3.3 15% sulfuric acid/phosphoric acid mixed acid
Add 150 mL of sulfuric acid (ρ 1.84 g/mL) to 500 mL of water. After cooling, slowly
add 150 mL of phosphoric acid (ρ 1.69 g/mL). After cooling, dilute with water to 1 L.
Mix well.
B.3.4 Tin dichloride solution, 50 g/L
Weigh 5 g of tin dichloride and dissolve it in 10 mL of hydrochloric acid (see B.3.2).
Dilute to 100 mL with water (if the solution is turbid, filter it) and set aside.
B.3.5 Sodium diphenylamine sulfonate indicator
Weigh 0.5 g of sodium diphenylamine sulfonate and dissolve it in water. Dilute with
water to 100 mL of water. Mix well and set aside.
B.3.6 Titanium trichloride solution, 20 g/L
Measure 10 mL of 20% TiCl3 and add 20 mL of hydrochlor...
Delivery: 9 seconds. Download (& Email) true-PDF + Invoice.
Get Quotation: Click GB/T 30835-2014 (Self-service in 1-minute)
Historical versions (Master-website): GB/T 30835-2014
Preview True-PDF (Reload/Scroll-down if blank)
GB/T 30835-2014
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 29.050
Q 53
Lithium iron phosphate-carbon composite cathode materials
for lithium ion battery
ISSUED ON: JUNE 24, 2014
IMPLEMENTED ON: APRIL 01, 2015
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 5
4 Classification and codes ... 5
5 Technical requirements ... 6
6 Test methods ... 7
7 Inspection rules ... 9
8 Packaging, marks ... 11
9 Storage and transportation ... 11
Annex A (normative) Method for determination of lithium content (excluding carbon
content) ... 13
Annex B (normative) Method for determination of iron content (excluding carbon
content) ... 17
Annex C (normative) Method for determination of phosphorus content (excluding
carbon content) ... 21
Annex D (informative) Method for determination of crystal structure ... 26
Annex E (normative) Method for determination of iron ion dissolution rate ... 29
Annex F (normative) Method for determination of first coulombic efficiency, first
reversible specific capacity, rate performance ... 33
Annex G (normative) Method for determination of conductivity ... 38
Lithium iron phosphate-carbon composite cathode materials
for lithium ion battery
1 Scope
This Standard specifies the terms and definitions, classification and codes, technical
requirements, test methods, inspection rules and packaging, marking, storage and
transportation for lithium iron phosphate-carbon composite cathode materials for
lithium ion battery.
This Standard applies to lithium iron phosphate-carbon composite cathode materials for
lithium ion battery.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 191, Packaging and storage marks
GB/T 5162, Metallic powders -- Determination of tap density
GB/T 6283, Chemical products -- Determination of water Karl-Fischer method
(general method)
GB/T 6388, Transport package shipping mark
GB/T 6682, Water for analytical laboratory use -- Specification and test methods
GB/T 9724, Chemical reagent -- General rule for the determination of pH
GB/T 12805, Laboratory glassware -- Burettes
GB/T 13732, General rules for sampling inspection of bulk materials with uniform
size
GB/T 19077.1, Particle size analysis -- Laser diffraction methods -- Part 1: General
principles
GB/T 19587, Determination of the specific surface area of solids by gas adsorption
using the BET method
GB/T 20123, Steel and iron -- Determination of total carbon and sulfur content
Infrared absorption method after combustion in an induction furnace (routine
method)
GB/T 24533-2009, Graphite negative electrode materials for lithium ion battery
JCPDS (01-077-0179), Lithium iron phosphate X-ray powder diffraction standard
pattern
IEC 62321, Electrotechnical products - Determination of levels of six regulated
substances (lead, mercury, cadmium, hexavalent chromium, polybrominated
biphenyls, polybrominated diphenyl ethers)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 lithium iron phosphate-carbon composite cathode materials
Lithium-ion battery cathode material composed of lithium iron phosphate and carbon
with an olivine structure. Lithium iron phosphate belongs to the orthorhombic crystal
system. It has a one-dimensional lithium embedded channel. Lithium ions can be
reversibly deintercalated within the crystal lattice. The theoretical specific capacity of
the material is 170 mA·h/g.
NOTE: LFP@C mentioned in this Standard all represents lithium iron phosphate-carbon composite
cathode materials.
4 Classification and codes
4.1 Product classification
Lithium iron phosphate-carbon composite cathode materials are divided into energy
type and power type according to charge and discharge characteristics and usage
requirements, represented by LFP@C-E and LFP@C-P respectively. LFP represents
lithium iron phosphate, @ represents the composite of two materials, C represents
carbon, E represents energy type, and P represents power type:
- Energy type lithium iron phosphate-carbon composite cathode materials (LFP@C-
E) are divided into three categories, represented by LFP@C-E-Ⅰ, LFP@CE-Ⅱ,
and LFP@C-E-Ⅲ. The specific performance requirements are detailed in Table
2;
- Power type lithium iron phosphate-carbon composite cathode materials (LFP@C-
P) are divided into three categories, represented by LFP@C-P-Ⅰ, LFP@CP-Ⅱ, and
LFP@C-P-Ⅲ. The specific performance requirements are detailed in Table 2.
6.17 Conductivity
Measure according to the measurement method specified in Annex G.
6.18 Restricted substance content
The measurement is carried out according to the measurement method specified in IEC
62321.
7 Inspection rules
7.1 Sampling method
7.1.1 Sampling
7.1.1.1 Lithium iron phosphate-carbon composite cathode materials for bagged lithium-
ion batteries shall be sampled in accordance with GB/T 13732. Open the bag of lithium
iron phosphate-carbon composite cathode material to be collected in a dry environment.
Use a clean stainless steel sampling drill to insert into the bag along the axis. The
insertion depth shall not be less than 4/5 of the depth of the sampling bag. Samples are
taken within 20 mm around the central axis of the material in the bag.
7.1.1.2 In order to make the collected samples represent the quality of this batch of
products, all collected samples are combined. Place on a square film of sufficient
strength and appropriate size or firm, soft drying paper. Mix evenly by rolling
repeatedly (turn more than 15 times). The mixed sample shall not be less than 500 g.
Cut off two 250 g specimens, one for testing and one for backup.
7.1.2 Sample label
After the sample is placed in the PVC sample jar, a label is immediately attached to the
outer wall. The label includes the following:
a) Sample type and number;
b) Overall material batch number and quantity;
c) Sample size;
d) Sampling date;
e) Name of sampler.
7.1.3 Storage of samples
7.1.3.1 Samples shall be sealed and stored in anti-breakage bags, rain-proof, moisture-
proof and other environments.
7.1.3.2 The effective storage period of spare samples is 12 months.
7.2 Inspection
7.2.1 Exit-factory inspection
Inspect the particle size, carbon content, moisture content, BET specific surface area,
tap density, electrochemical performance, iron ion dissolution amount, conductivity and
other indicators of each batch of samples. They can be shipped only after passing the
inspection.
7.2.2 Type inspection
All technical requirements specified in this Standard shall be inspected. Type inspection
is carried out when one of the following situations occurs:
a) When there are changes in raw material models, supplier manufacturers, etc.;
b) When there are changes in the production process;
c) When the production equipment has been shut down for more than half a year and
then starts production for the first time;
d) When customers have special requirements.
7.3 Acceptance rules
7.3.1 Products that meet all the technical indicators required by a certain category in
Table 2 are qualified products. If an indicator fails to meet the requirements of this
category, double samples shall be taken from the sampling bags of the same batch of
products to re-inspect the unqualified items. The re-inspection results shall be taken as
the final result. Products that do not fall into the product categories in Table 2 or have
special requirements must be determined through negotiation between the supplier and
the purchaser to determine whether they are qualified.
7.3.2 The inspection department of the manufacturer shall ensure that the products
shipped meet the requirements of this Standard. When each batch of products leaves
the factory, a product quality inspection report is sent to the recipient.
7.3.3 The consignee has the right to accept products in accordance with this Standard
and the right to reject products that do not meet the requirements of this Standard.
7.3.4 The consignee shall conduct acceptance inspection of the product within one
month after receiving the product. If there is any objection, a spare sample shall be used
for re-inspection. If there is still a dispute, it will be arbitrated by the superior quality
supervision department.
Annex A
(normative)
Method for determination of lithium content (excluding carbon content)
A.1 Scope of application
This appendix is applicable to the determination of lithium content (except carbon
content) in specimens by inductively coupled plasma optical emission spectrometry.
A.2 Method summary
The specimen is dissolved in hydrochloric acid. In hydrochloric acid medium,
according to the optimized working conditions of the instrument, use the working curve
method and the inductively coupled plasma emission spectrometer to measure the
lithium ion content.
A.3 Reagents and materials
Without special instructions, the water used in the tests in this Standard refers to water
that meets the requirements in GB/T 6682 for the grade three water. All reagents used
in the test are analytically pure.
A.3.1 Concentrated hydrochloric acid
ρ 1.19 g/mL.
A.3.2 Argon gas
The volume fraction is not less than 99.999%.
A.3.3 Lithium standard solution
The concentration is 1000 μg/mL. It is a national certified standard sample and can be
stored for 1 year.
A.3.4 Preparation of reserve standard solutions
Take 5.00 mL of lithium standard solution (see A.3.3) in a 100 mL volumetric flask.
Add 2.00 mL of concentrated hydrochloric acid (see A.3.1). Add water and set the
volume constant to the scale. Shake well. Prepare a stock standard solution with a
lithium ion concentration of 50.00 μg/mL.
A.3.5 Preparation of series of standard solutions
Accurately measure 0 mL, 1.00 mL, 2.00 mL, 5.00 mL, and 10.00 mL of lithium ion
reserve standard solutions (see A.3.4) and place them into five 100 mL volumetric flasks.
Add 2.00 mL of concentrated hydrochloric acid to each (see A.3.1). Add water and set
the volume constant to the scale. Shake well. Prepare standard sample blanks and a
series of standard solutions with lithium ion concentrations of 0 μg/mL, 0.50 μg/mL,
1.00 μg/mL, 2.50 μg/mL, and 5.00 μg/mL. The ion content in the solution to be tested
shall be within the range of the standard curve.
A.4 Instruments and equipment
A.4.1 Inductively coupled plasma emission spectrometer.
A.4.2 Microwave digestion apparatus (including sample tank) or digestion device with
equivalent performance.
A.4.3 Electronic balance (resolution: 0.0001 g).
A.5 Analysis steps
A.5.1 Number of measurements
Take two samples for parallel sample testing. Take the arithmetic mean.
A.5.2 Blank test
Do a blank test along with the specimen.
A.5.3 Standard curve
Linear correlation coefficient ≥0.9995.
A.5.4 Preparation of sample solution to be tested
Weigh 0.10 g ± 0.02 g (accurate to 0.0001 g) of specimen into a clean sample jar. Add
9.00 mL of concentrated hydrochloric acid (see A.3.1). Place in microwave digestion
apparatus (see A.4.2). After digestion is complete, cool to room temperature. Filter and
set the volume constant. Dilute the sample solution to a constant volume appropriately
(refer to the preparation method of the reserve standard solution for dilution). Ensure
that the lithium ion concentration in the sample solution to be tested is within the
standard curve.
A.5.5 Determination
After the instrument is running stably, in accordance with the conditions in Table A.1,
inject the standard sample blank and the series of standard solutions (see A.3.6) in
sequence for measurement. Draw a curve. Then measure the specimen blank and the
sample solution to be tested (see A.5.4) in the same way. Use blank subtraction to
correct the results.
Annex B
(normative)
Method for determination of iron content (excluding carbon content)
B.1 Scope of application
This appendix is applicable to the potassium dichromate standard solution titration
method for determining the total iron content (except carbon content) in the specimen.
B.2 Method summary
After the specimen is dissolved with perchloric acid, CuSO4-isatin is used as the
indicator, and tin dichloride and titanium trichloride are used to reduce the ferric iron
to divalent iron. Use sodium diphenylamine sulfonate as indicator and potassium
dichromate standard solution for titration test.
B.3 Reagents and materials
Without special instructions, the water used in this Standard test refers to grade three
water specified in GB/T 6682, and the reagents used in the test are all analytically pure.
B.3.1 Perchloric acid, ρ 1.76 g/mL
Guaranteed reagent.
B.3.2 Hydrochloric acid, 1:1
Dilute with hydrochloric acid (ρ 1.19 g/mL) and water at a volume ratio of 1:1.
B.3.3 15% sulfuric acid/phosphoric acid mixed acid
Add 150 mL of sulfuric acid (ρ 1.84 g/mL) to 500 mL of water. After cooling, slowly
add 150 mL of phosphoric acid (ρ 1.69 g/mL). After cooling, dilute with water to 1 L.
Mix well.
B.3.4 Tin dichloride solution, 50 g/L
Weigh 5 g of tin dichloride and dissolve it in 10 mL of hydrochloric acid (see B.3.2).
Dilute to 100 mL with water (if the solution is turbid, filter it) and set aside.
B.3.5 Sodium diphenylamine sulfonate indicator
Weigh 0.5 g of sodium diphenylamine sulfonate and dissolve it in water. Dilute with
water to 100 mL of water. Mix well and set aside.
B.3.6 Titanium trichloride solution, 20 g/L
Measure 10 mL of 20% TiCl3 and add 20 mL of hydrochlor...
Share











