Method of test for determination of the chemical composition of asbestos fibre

IS 5328 - 1969 (Reaffirmed 2001): Scope Overview

IS 5328 covers design and construction of structural glass elements, focusing on safety and performance.

Key Points on Scope:

• Applies to glass used in buildings and structures.
• Covers methods for calculating stresses and design of glass panels.
• Includes special shapes like glass triangles (Clause 6.1.4).
• Addresses loadings, support conditions, and edge treatments.

Important Specifications:

• Glass thickness and type as per loading and span.
• Allowable stress limits for glass based on type (annealed, toughened).
• Support details to avoid stress concentrations.

Typical Formula for Glass Stress (Bending):

[ \sigma = \frac{6 \times M}{b \times t^2} ]

Where:

• (\sigma) = bending stress
• (M) = bending moment
• (b) = width of glass
• (t) = thickness of glass

Glass Triangle (Clause 6.1.4):

• Special consideration for stress concentration at corners.
• Use reinforcements or edge treatments to reduce risk.

flowchart TD
    A[Glass Panel] --> B{Shape?}
    B -->|Rectangular| C[Standard Stress Calculation]
    B -->|Triangle| D[Apply Clause 6.1.4]
    D --> E[Edge Reinforcement]
    D --> F[Stress Concentration Checks]

For detailed design, refer to IS 5328 clauses on thickness, load factors, and support conditions.

IS 5328 - Outline of Method: Key Formulas & Specifications

1. Outline of Method (Clause 1.1: 2)

• The method involves chemical analysis to determine oxide percentages in samples.
• Key oxides analyzed: Silica (SiO₂), Ferrous oxide (FeO), Ferric oxide (Fe₂O₃), Carbon dioxide (CO₂).

2. Key Formulas

3. Specifications

• Sample weight (W) is critical for all calculations.
• Use volumetric titration (permanganate solution) for ferrous oxide.
• Absorption method for CO₂ determination.

4. Summary Diagram

flowchart TD
    A[Sample Preparation] --> B[Chemical Treatment]
    B --> C[Silica Determination]
    B --> D[Ferrous Oxide Titration]
    B --> E[CO2 Absorption]
    C --> F[Calculate % Silica]
    D --> G[Calculate % FeO]
    E --> H[Calculate % CO2]

This concise method ensures accurate oxide percentage determination as per IS 5328.

IS 5328: Sampling & Preparation of Laboratory Test Specimen

Key Points from IS 5328 & Related IS Codes (IS 4844-1968):

1. Sampling (Clause 13.3)

• Take a specimen ~1 g from the laboratory test sample.
• Dry at 110°C until constant weight.
• Weigh to nearest 0.001 g; denote weight as W grams.

2. Preparation of Specimen (Clause 4.1)

• Quarter the lab sample to ~25 g.
• Divide into 10 equal parts, then halve each part.
• Combine halves and mix; repeat until reduced to ~3 g.
• Spread 3 g thinly over ~20 cm x 20 cm area.
• Extract 5 bundles of long fiber (~0.5 g each), free from impurities.
• Combine and dry these fibers at 110°C to get test specimen weighing 0.5 ± 0.02 g.

3. Drying Conditions

• Dry at 110°C to constant weight (to remove moisture).
• Weigh with precision of ±0.001 g.

Summary Table for Sample Preparation

Notes:

• If bromine water is unavailable for oxidation, use concentrated nitric acid or hydrogen peroxide.
• Follow IS 4844-1968 for detailed sampling methods.

flowchart TD
    A[Laboratory Sample] --> B[Quarter to ~25g]
    B --> C[Divide into 10 equal parts]
    C --> D[Halve each part]
    D --> E[Combine halves & mix]
    E

IS 5328: Preparation of Laboratory Test Specimen - Key Points

Sampling and Sample Preparation (Clauses 3.1, 4.1, 13.3)

• Sample Size & Initial Preparation:

  • Start with laboratory test sample per IS:4844-1968.
  • Quarter down to ~25 g.
  • Divide into 10 equal portions → halve each → combine halves → repeat until ~3 g remains.

• Spreading & Fiber Extraction:

  • Spread 3 g thinly over ~20 x 20 cm area.
  • Extract 5 bundles of long fiber (~0.5 g each) free from contaminants.
  • Combine and dry bundles at 110°C to constant weight.

• Final Test Specimen:

  • Weight = 0.5 ± 0.02 g after drying at 110°C.
  • Dry specimen to constant weight (110°C).
  • Weigh to nearest 0.001 g.

Drying & Weighing Formula:

[ W = \text{Weight after drying at 110°C to constant weight} ]

Where (W) ≈ 0.5 g ± 0.02 g for test specimen.

Notes:

• If bromine water is unavailable for oxidation, use concentrated nitric acid or hydrogen peroxide.
• Follow IS:2-1960 for rounding off numerical values.
• Refer IS:4844-1968 for detailed sampling and preparation methods.

flowchart TD
    A[Laboratory Sample] --> B[Quarter to ~25g]
    B --> C[Divide into 10 portions]
    C --> D[Halve each portion]
    D --> E[Combine halves & mix]
    E --> F[Repeat until ~3g]
    F --> G[Spread thin on 20x20 cm]
    G --> H[Extract 5 fiber bundles (~0.5g each)]
    H --> I[Dry at 110°C to constant weight]
    I --> J[Test Specimen: 0.5 ± 0.02 g]

This ensures representative, contaminant-free, and standardized test specimens for chemical and physical analysis of asbestos fiber.

IS 5328: Apparatus & Equipment Key Specifications

Knorr Alkalimeter Components (Clause 13.1.2)

• Gas Washing Bottle A: Contains concentrated H₂SO₄ to indicate flow rate & block moisture.
• Drying Tube B: 2/3 soda-asbestos (ascarite) + 1/3 drying agent to remove CO₂.
• Knorr Alkalimeter Unit C: Includes dropping funnel, distillation flask, condenser (standard taper joints).
• Gas Washing Bottle D: 5-10% silver sulphate in H₂SO₄ to absorb moisture & HCl.
• Drying Tube E: Copper sulphate to absorb H₂S.
• Drying Tube F: Suitable drying agent for complete drying.
• Absorption Tube G: 2/3 soda-asbestos + 1/3 drying agent for CO₂ absorption.
• Absorption Tube H: Reverse fill of drying agent + soda-asbestos to prevent CO₂ entry.
• Trap J: Prevents backflow from aspirator.
• Valve/Pinched Tubing K: Controls air flow rate.

Electric Furnace (Clauses 5.1.4 & 14.1.2)

• Operating temperature: 925°C ± 25°C

Desiccator (Clause 10.1.6)

• Used for moisture removal and sample drying.

Summary Table: Knorr Alkalimeter Tube Fillings

flowchart LR
    A[Gas Washing Bottle A]
    B[Drying Tube

IS 5328: Determination of Silica by Hydrofluoric Acid (Gravimetric) Method

Key Steps & Specifications:

• Sample Preparation (Clause 12.3.1):

  • Take 1 g powdered sample in a platinum crucible.
  • Add 5 ml dilute H2SO4 (1:5 v/v), mix well.
  • Add 5 ml concentrated HF, evaporate until H2SO4 fumes appear.
  • Repeat HF addition & evaporation until complete decomposition.
  • Expel excess H2SO4 and fluorine by heating.

• Purification (Clause 6.3.7):

  • Moisten impure silica with water.
  • Add a drop of concentrated H2SO4 (sp. gr. 1.18) + 5-10 ml HF.
  • Evaporate in air bath until no vapors.
  • Remove excess H2SO4 by flame heating.
  • Final heating with Meker burner, then weigh.

• Constant Weight & Correction (Clause 6.3.8):

  • Repeat treatment with H2SO4 and HF without water until constant weight.
  • Weight is usually ferric oxide + alumina.
  • Deduct this from impure silica weight.
  • Add this correction to subsequent ammonia precipitate weight.

Summary Table:

flowchart TD
    A[Sample (1 g)] --> B[Add dilute H2SO4 (5 ml)]
    B --> C[Add HF (5 ml) & Evaporate]
    C --> D{Complete decomposition?}
    D -- No --> C
    D -- Yes --> E[Expel excess acid & fluorine]
    E --> F[Purify silica with H2SO4 + HF]
    F

IS 5328: Key Formulas for Determination of Ferrous and Ferric Oxides

1. Ferrous Oxide (%)

From Clause 7.4:
[ \text{Ferrous oxide, %} = \frac{\text{Volume of potassium permanganate (ml)} \times 0.0056 \times 1.28 \times 100}{\text{Weight of sample (g)}} ]

• 0.0056 = equivalent weight factor of potassium permanganate
• 1.28 = factor for FeO molecular weight adjustment

2. Ferric Oxide (%)

From Clause 8.4:
[ \text{Ferric oxide, %} = \frac{\text{Volume of potassium dichromate (ml)} \times 0.0056 \times 2 \times 1.43 \times 100}{\text{Weight of sample (g)}} ]

• 0.0056 = equivalent weight factor of potassium dichromate
• 2 = stoichiometric factor for Fe³⁺ to Fe²⁺ conversion
• 1.43 = molecular weight factor for Fe₂O₃

3. Silica (%)

From Clause 6.4:
[ \text{Silica, %} = \frac{\text{Weight of silica (g)} \times 100}{\text{Weight of sample (g)}} ]

Notes on Procedure (Clause 8.3.5 for Al₂O₃):

• Ferric iron reduced by stannous chloride at 80°C until yellow color disappears.
• After cooling, mercuric chloride added to form precipitate.
• Titration with potassium dichromate standardized such that 1 ml = 0.0056 g Fe.

flowchart TD
    A[Sample Preparation] --> B[Add Stannous Chloride]
    B --> C[Reduction of Fe³⁺ to Fe²⁺]
    C --> D[Add Mercuric Chloride]
    D --> E[Formation of Precipitate]
    E --> F[Titrate with K2Cr2O7]
    F --> G[Calculate Fe₂O₃ %]
``

IS 5328: Key Formulas for Determination of Ferric Oxide

1. Ferric Oxide Percentage (Clause 8.4)

[ \text{Ferric oxide, %} = \frac{\text{Volume of potassium dichromate titer in ml} \times 0.0056 \times 2 \times 1.43}{\text{Weight of sample (g)}} \times 100 ]

• 0.0056 = Normality factor of dichromate
• 2 = Equivalent factor for Fe2O3
• 1.43 = Molecular weight ratio (Fe2O3 / Fe)

2. Ferrous Oxide Percentage (Clause 7.4)

[ \text{Ferrous oxide, %} = \frac{\text{Volume of potassium permanganate in ml} \times 0.0056 \times 1.28}{\text{Weight of sample (g)}} \times 100 ]

• 0.0056 = Normality factor of permanganate
• 1.28 = Molecular weight ratio (FeO / Fe)

3. Total Alumina and Ferric Oxide (Clause 8.3.3)

[ \text{Total alumina + ferric oxide, %} = \frac{\text{Weight of alumina + ferric oxide in crucible}}{\text{Weight of sample (W)}} \times 100 ]

Notes:

• Use accurate titration volumes and sample weights.
• Ensure complete ignition and drying before weighing.
• These formulas are essential for chemical analysis of iron ores and related materials.

flowchart TD
    A[Sample Preparation] --> B[Titration with KMnO4 or K2Cr2O7]
    B --> C[Measure Volume of Titrant]
    C --> D[Apply Formula for FeO or Fe2O3]
    D --> E[Calculate % of Oxide]

This concise summary covers the essential formulas and steps for ferric oxide determination as per IS 5328.

IS 5328: Determination of Aluminium Oxide (Al₂O₃)

Key Specifications & Formulas:

1. Total Ferric Oxide + Aluminium Oxide (Clause 8.3.3):

[ \text{Total Al}_2\text{O}_3 + \text{Fe}_2\text{O}_3 % = \frac{\text{Weight of ignited residue (Al}_2\text{O}_3 + \text{Fe}_2\text{O}_3)}{\text{Weight of sample (W)}} \times 100 ]

2. Ferric Oxide % (Clause 8.4):

[ \text{Fe}_2\text{O}_3 % = \frac{\text{Volume of potassium dichromate titer (ml)} \times 0.0056 \times 2 \times 1.43}{\text{Weight of sample (W)}} \times 100 ]

3. Aluminium Oxide % (Clause 9.1):

[ \text{Al}_2\text{O}_3 % = (\text{Total Al}_2\text{O}_3 + \text{Fe}_2\text{O}_3) % - \text{Fe}_2\text{O}_3 % ]

Summary:

• Step 1: Measure total Fe₂O₃ + Al₂O₃ by ignition residue.
• Step 2: Determine Fe₂O₃ volumetrically using potassium dichromate.
• Step 3: Calculate Al₂O₃ by difference.

This method ensures accurate separation of aluminium oxide content from ferric oxide in the sample.

flowchart LR
    A[Sample] --> B[Ignite residue]
    B --> C[Weight = Fe₂O₃ + Al₂O₃]
    A --> D[Volumetric titration with K₂Cr₂O₇]
    D --> E[Fe₂O₃ %]
    C --> F[Total Fe₂O₃ + Al₂O₃ %]
    E --> G[Calculate Al₂O₃ % = Total - Fe₂O₃]

Note: For calcium oxide determination, refer to Clause 10

IS 5328: Determination of Calcium Oxide by Oxalate (Gravimetric) Method

Key Steps & Specifications:

• Sample Preparation: Treat silicate samples by fusion with sodium carbonate, dissolve in HCl, remove silica by precipitation.
• Filtrate Treatment: Oxidize iron to ferric state with bromine water; precipitate Fe₂O₃ + Al₂O₃ with ammonia; separate iron volumetrically and alumina by 8-hydroxyquinoline.
• Calcium Oxalate Precipitation: From acidified filtrate, precipitate calcium as calcium oxalate.
• Ignition: Collect precipitate on filter paper, wash free of chlorides, transfer to weighed crucible, ignite carefully to constant weight.

Calculation Formula (Clause 10.4):

[ \text{Calcium Oxide %} = \frac{\text{Weight of CaO (ignited precipitate)}}{\text{Weight of sample (W)}} \times 100 ]

Important Notes (Clause 10.3.4):

• Ignite precipitate gradually: dry → decompose filter paper → heat at high temp (Meker burner) for 1 hour.
• Cool to ~100°C, desiccate 15 min, weigh repeatedly until constant weight (±0.2 mg).
• Calcium oxide is hygroscopic; thorough washing is essential.

Summary Flow Diagram:

flowchart TD
    A[Sample Fusion with Na2CO3] --> B[Dissolve in HCl]
    B --> C[Remove Silica by Precipitation]
    C --> D[Oxidize Fe to Fe³⁺ with Bromine Water]
    D --> E[Precipitate Fe₂O₃ + Al₂O₃ with NH₄OH]
    E --> F[Separate Fe volumetrically, Al by 8-hydroxyquinoline]
    F --> G[Filtrate contains Ca & Mg]
    G --> H[Acidify Filtrate]
    H --> I[Precipitate Ca as Calcium Oxalate]
    I --> J[Filter, Wash, Ignite to CaO]
    J --> K[Weigh CaO → Calculate % CaO]

This method ensures precise gravimetric determination of CaO in silicate samples per IS 5328.

Determination of Magnesium Oxide (IS 5328)

Key Formula (Clause 11.4)

[ \text{Magnesium oxide (%)} = \frac{\text{Weight of magnesium pyrophosphate (Mg}_2\text{P}_2\text{O}_7) \times 0.3621}{\text{Weight of sample (W)}} \times 100 ]

Procedure Highlights (Clause 11.3.3)

• Filter magnesium ammonium phosphate precipitate.
• Wash with 1.5 N ammonium hydroxide.
• Moisten with saturated ammonium nitrate in 1.5 N ammonium hydroxide.
• Dry and ignite slowly at 1000°C to 1100°C.
• Weigh the residue (contains approx. 36.21% MgO).

Notes

• The factor 0.3621 converts Mg₂P₂O₇ weight to MgO weight.
• Ensure constant weight by repeated ignition and cooling.

Summary Table

This method ensures accurate MgO content determination in mineral samples.

IS 5328 - Determination of Sodium Oxide (Na2O)

Key Formula (Clause 12.4):

[ \text{Sodium oxide, %} = \frac{62 \times W \times 100}{235 - 45 \times W} ]

• W = Weight of sodium-zinc uranyl acetate obtained from 1 gram of the sample.

Explanation:

• Sodium oxide is determined by precipitating sodium as sodium-zinc uranyl acetate.
• The weight of this precipitate (W) is used in the formula to calculate % Na2O.

Related Oxide Calculations (for reference):

If you want, I can provide a flowchart for the Sodium Oxide determination process.

IS 5328: Determination of Carbon Dioxide from Carbonates

Key Specifications & Apparatus (Clause 13.1.2)

• Knorr Alkalimeter Setup includes:
  • Gas washing bottles (A, D) with concentrated sulfuric acid and silver sulfate solution.
  • Drying tubes (B, E, F, H) with soda-asbestos (ascarite), drying agents, copper sulfate.
  • Knorr alkalimeter unit (C): dropping funnel, distillation flask, condenser.
  • Absorption tubes (G, H) for CO₂ absorption.
  • Trap (J) and valve (K) to control airflow.

Procedure Summary (Clause 13.4.2)

• Weigh ~1 g sample.
• Add 50 ml HCl (1:1) slowly into flask.
• Air is drawn through system at 2-3 bubbles/sec.
• Warm to boiling, then cool; continue airflow for 30 min.
• Increase in absorption bulb weight = CO₂ absorbed.

Calculation Formula (Clause 13.5)

[ \boxed{ \text{Carbon dioxide, %} = \frac{\text{Weight of CO}_2 \text{ absorbed}}{\text{Weight of sample } (W)} \times 100 } ]

Summary Diagram (Knorr Alkalimeter Flow)

flowchart LR
    A[Gas washing bottle (H2SO4)] --> B[Drying tube (Ascarite)]
    B --> C[Knorr alkalimeter unit]
    C --> D[Gas washing bottle (Ag2SO4)]
    D --> E[Drying tube (CuSO4)]
    E --> F[Drying tube (Drying agent)]
    F --> G[Absorption tube (Ascarite)]
    G --> H[Absorption tube (reverse)]
    H --> J[Trap (water backflow)]
    J --> K[Valve (controls airflow)]

Note: Accurate weighing and controlled airflow are critical for precise CO₂ determination.

IS 5328: Electric Furnace & Heating Procedure Key Points

• Electric Furnace Temperature: Maintain at 925°C ± 25°C (Clauses 5.1.4 & 14.1.2).

• Heating Procedure (Clause 14.2):

  1. Dry sample to constant weight.
  2. Place sample in a tared porcelain crucible.
  3. Ignite in electric furnace at 925°C ± 25°C for 1 hour.
  4. Cool in oven at 110°C.
  5. Further cool in a desiccator.
  6. Reweigh to nearest 0.001 g.

• Alternate Heating Devices: Radiator or hot plate can be used (Clause 12.1.3) but electric furnace preferred for uniformity.

Summary Table

flowchart TD
    A[Dry Sample to Constant Weight] --> B[Place in Tared Porcelain Crucible]
    B --> C[Ignite in Electric Furnace at 925°C ± 25°C for 1 Hour]
    C --> D[Cool in Oven at 110°C]
    D --> E[Cool in Desiccator]
    E --> F[Reweigh to nearest 0.001 g]

This procedure ensures accurate determination of residue or ignition loss per IS 5328.

Here are the key formulas and specifications from IS 5328 for calculations and reporting results:

Key Formulas

• (W) = Weight of the sample in grams.

Notes:

• For ferrous oxide and magnesium oxide, volumetric methods are used (Clause 7 and 11), but specific formulas are not provided here.
• Always report results as percentage by weight relative to the original sample.

Reporting Results:

• Express all results as percentage by weight.
• Use consistent units (grams for weight).
• Clearly state sample weight (W) used for calculations.

flowchart TD
    A[Sample Preparation] --> B[Measurement of constituent weight]
    B --> C[Apply formula (e.g. CO2 % = (Weight CO2 / W) × 100)]
    C --> D[Calculate percentage]
    D --> E[Report results as % by weight]

This ensures clarity and uniformity in reporting test outcomes per IS 5328.