Some standard content:
GB/T 2899—1996
This standard is revised on the basis of GB/T2899--82 "Precipitated Barium Sulfate". The superior powder products are equivalent to ISO3262:1975 "Fillers for Paints", and the first-class products are non-equivalent to ISO3262:1975 "Fillers for Paints". The main technical differences between this standard and ISO3262:1975 "Fillers for Paints" are as follows: 1. The scope of application of this standard is industrial use. In order to be applicable to various industries, the products are divided into two types: powder and paste, and the powder is divided into three levels. The ISO 3262 standard is for paints and has only one level. 2. The index items of this standard have two more items than ISO3262: iron content and oil absorption. The index parameters of the superior and first-class products of this standard are equal to or better than ISO3262, and the qualified products are close to the ISO3262 standard. 3 Analysis method: The same items as ISO3262 are equivalent to or equivalent to ISO3262 standard. The determination of iron content adopts GB/T3049-86 "General method for determination of iron content in chemical products - o-phenanthroline spectrophotometry", which is not equivalent to ISO6685:1982 standard.
Important technical content changes between this standard and GB/T2899-82: 1GB/T2899--82 divides powder products into two levels: first-class and second-class products, while this standard divides products into three levels: superior products, first-class products and qualified products.
2 The two indicators of acetic acid soluble content and sulfide content are removed. 3 Analysis method: Whiteness is determined by whiteness meter, and pH value is determined by GB/T1717--86 method. This pigment general method standard is equivalent to ISO787/9:1981 method. This standard replaces GB/T2899-82 from the date of entry into force. This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Tianjin Chemical Research Institute of the Ministry of Chemical Industry. The drafting units of this standard are: Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Qingdao Dongfeng Chemical Plant, Hebei Xinji Chemical Plant, Shanxi Yuncheng Salt Chemical Bureau, Shaanxi Fuping Chemical Plant.
The main drafters of this standard are: Zhang Aishan, Wang Fanfan, Hao Baoyu, Fan Jianxia, Chen Yongkang, Zhang Jingjuan. This standard was first issued in 1982.
1 Scope
National Standard of the People's Republic of China
Industrial precipitated barium sulfate
Barium sulphate, precipitatedfor industrial use
GB/T 2899—1996
Replaces GB/T2899—82
This standard specifies the requirements, sampling, test methods, marking, packaging, transportation and storage of industrial precipitated barium sulfate. This standard applies to industrial precipitated barium sulfate. This product is mainly used in paint, ink, pigment, rubber, battery, plastic and coated paper industries.
Molecular formula: BaSO,
Relative molecular mass: 233.40 (according to the relative atomic mass in 1991) 2, Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in the standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. GB191-90 Pictorial markings for packaging, storage and transportation
Preparation of standard solutions for titration analysis (volume analysis) of chemical reagents GB/T 601--88
GB/T 602—88
Preparation of standard solutions for determination of impurities in chemical reagents (negISO6353/1:1982) GB/T603—88 Preparation of preparations and products used in test methods for chemical reagents (neqISO6353/1:1982) GB/T 1250-89
9Expression and determination method of limit valuesGB/T1717--86Determination of pH value of aqueous suspension of pigments (eqvISO787-9:1981)General method for determination of iron content in chemical productsPhenanthroline spectrophotometric method (neqISO6685: GB/T3049--861
GB/T5211.2-85Determination of water-soluble matter in pigmentsThermal extraction method (negISO787-3:1976)GB/T5211.3--85Determination of volatile matter of pigments at 105℃ (eqvISO787-2:1981)GB/T5211.15-88Determination of oil absorption of pigments (eqvISO787-5:1980)GB/T5 950--86 General rules for whiteness test methods for building materials and non-metallic mineral products GB/T6003--85 Test sieves
GB/T6678-86 General rules for sampling of chemical products GB/T6682--92 Specifications and test methods for water used in analytical laboratories (eqvISO3696:1987) GB/T894688 Plastic woven bags
GB/T8947--88 Composite plastic woven bags
3 Classification
Class 1: Powder, used in pigments, inks, rubber, batteries, plastics and other industries. Class I: Paste, mainly suitable for industries such as copperplate paper. Approved by the State Bureau of Technical Supervision on December 2, 1996 and implemented on May 1, 1997
4 Requirements
GB/T 2899-1996
4.1 Appearance: amorphous white powder or white paste. ,4.2 Industrial precipitated sulfuric acid should meet the requirements of Table 1. Table 1 Requirements
Barium sulfate (BaS()) content (based on basis), %≥105℃ volatile matter, %
Water-soluble matter content, %
Iron (Fe) content, %
Whiteness, %
Oil absorption g/100g
pH value (100g/L suspension)
Fineness (45 μm test sieve residue), %Particle size distribution
Less than 10 μm, %
Less than 5 μm, %
Less than 2 μm,%
5 Sampling
5.1 Each batch of products shall not exceed 100t.
Superior products
Qualified products
5.2 Determine the number of sampling units according to the provisions of 6.6 in GB/T6678--86. When sampling, insert the sampler obliquely from the top of the packaging bag to three-quarters of the depth of the material layer to take samples. Mix the sampled products thoroughly, reduce them to about 1000g by quartering method, and put them into two clean and dry ground-mouth bottles. Stick labels on the bottles and indicate: manufacturer name, product name, category, grade, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample, and the other bottle is kept for three months for reference. 5.3 If one of the test results does not meet the requirements of this standard, sampling should be verified from twice the amount of packaging. Even if only one of the test results does not meet the requirements of this standard, the entire batch of products will be unqualified. 6 Test methods
6.1 All nine index items specified in this standard are type test items, among which the content of sulfate lock, volatile matter at 105℃, water-soluble matter content, pH value, whiteness, oil absorption and fineness are routine test items and should be tested batch by batch. Under normal production conditions, a type test is conducted once a month.
6.2 The rounded value comparison method specified in 5.2 of GB/T1250--89 is used to determine whether the test results meet the standard. 6.3 The reagents and water used in this standard, unless otherwise specified, refer to analytical pure reagents and grade 3 water specified in GB/T6682--92.
The standard solutions, impurity standard solutions, preparations and products required in the test, unless otherwise specified, are prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603.
6.4 Determination of barium sulfate content
6.4.1 Summary of the method
Melting the sample with a mixture of sodium carbonate and potassium carbonate at high temperature, the barium sulfate is converted into barium carbonate, and the barium carbonate is dissolved with hydrochloric acid to form barium chloride, which is then determined by the barium sulfate gravimetric method. 6.4.2 Reagents and materials
GB/T 2899-1996
6.4.2.1 Molten mixture: Mix anhydrous sodium carbonate and potassium carbonate in a ratio of 1+1. 6.4.2.2 Anhydrous sodium carbonate: 2g/1 solution. 6.4.2.3 Sulfuric acid: 1+9 solution.
6.4.2.4 Hydrochloric acid: 1+4 solution.
6.4.2.5 Ammonia water: 1+1 solution.
6.4.2.6 Chloride: 120g/L solution.
6.4.2.7 Silver nitrate: 20g/L solution.
6.4.2.8 Methyl orange indicator: 1g/L solution. 6.4.3 Instruments and equipment
6.4.3.1 Platinum crucible: with lid.
6.4.3.2 High temperature electric furnace: capable of controlling the temperature of 800±20℃ and 600±20℃. 6.4.4 Analysis steps
Weigh about 1g according to 6.5. Place the dried sample, accurate to 0.0002g, in a platinum crucible with 4g of molten mixture added, mix well, then cover it with 4g of molten mixture, cover it with a lid, place the crucible in a high-temperature electric furnace, melt at 800±20C for 40min, take it out and cool. Use 100-150mL hot water to soak the molten material in a 250mL beaker, and use a glass rod with a rubber head to transfer all the white molten material to the beaker. Heat and boil until the molten material is loose, let it stand for a while, filter the upper clear liquid with slow quantitative filter paper, then wash the insoluble matter with hot sodium carbonate solution by pouring method, and transfer it to the filter paper and continue washing until there is no sulfate (test method: take 2mL of filtrate, add 2 drops of hydrochloric acid solution and 0.5mL of barium chloride solution, and the solution should remain transparent after 10min). Add 30mL of hot hydrochloric acid solution to the funnel in six times to dissolve the precipitate. Collect the filtrate in a 500mL beaker. Wash with hot water after each addition of hydrochloric acid solution. After all the hydrochloric acid solution has been added, wash the filter paper on the funnel with hot water until there is no chloride ion (test method: take 2mL of filtrate, add 0.5mL of silver nitrate solution, and it should remain transparent after 5 minutes). Add 2 to 3 drops of methyl orange indicator solution to the filtrate, neutralize with ammonia water until it is just light yellow, add 2mL of hydrochloric acid solution, and finally add water to adjust the solution volume to 400mL.
Heat the solution to boiling, add 20mL of hot sulfuric acid solution at a uniform speed while stirring, and control the addition within 2 to 2.5 minutes. Cover the beaker, let it stand in a warm place for 3 hours or overnight, filter with slow quantitative filter paper, and wash the precipitate with hot water until there is no chloride ion in the filtrate (test method is the same as before). Place the precipitate and filter paper in a porcelain crucible that has been burned to constant weight, dry, ash, and burn to constant weight in a high-temperature electric furnace at 600 ± 20°C.
6.4.5 Expression of analysis results
The barium sulfate (BaSO,) content (X,) expressed as mass percentage is calculated according to formula (1): ml×100
Where: m1--mass of precipitate, g;
mass of sample, g.
6.4.6 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result, and the absolute difference of the parallel determination results shall not exceed 0.2%. 6.5 Determination of volatile matter at 105°C
Operate according to GB/T5211.3-85.
6.6 Determination of water-soluble matter content
Operate according to GB/T5211.2-85.
6.7 Determination of iron content
6.7.1 Summary of method
Same as Chapter 2 of GB/T3049-86.
6.7.2 Reagents and materials
Same as Chapter 3 of GB/T3049--86.
6.7.3 Instruments and equipment
Same as Chapter 4 of GB/T3049--86.
6.7.4 Drawing of working curve
GB/T 2899--1996
Draw the working curve according to the provisions of 5.3 of GB/T3049-86, using a 3 cm absorption cell and the corresponding amount of iron standard solution. 6.7.5 Analysis steps
6.7.5.1 Preparation of test solution
Weigh about 10g of sample, accurate to 0.01g, place in a 200mL beaker, add 100mL of water and 10mL of (1+1) hydrochloric acid solution, boil for 10min under stirring, and cool. Transfer all to a 250mL volumetric flask, dilute to scale with water, and shake well. Dry filter and discard the initial 20mL filtrate.
6.7.5.2 Preparation of blank test solution
In a 250mL volumetric flask, add 200mL of water and 10mL of (1+1) hydrochloric acid solution, dilute to scale with water, and shake well. 6.7.5.3 Determination
Use a pipette to transfer 25 mL of the test solution (6.7.5.1) and the blank test solution (6.7.5.2) into two 100 mL volumetric flasks, add water to about 60 mL, and adjust the pH to about 2 with (1+9) ammonia water (check with precision pH test paper). Follow the instructions in 5.3.2 of GB/T3049 and start from "add 2.5 mL of ascorbic acid solution...". Use a 3 cm absorption cell and measure the absorbance according to the provisions of 6.4.2 of GB/T3049. 6.7.6 Expression of analysis results
The iron (Fe) content (X2) expressed as mass percentage is calculated according to formula (2): X2 =
(mr mo)
m × 1 000 X
×100=
Wherein: mi——the mass of iron found from the working curve based on the measured absorbance of the test solution, mg; m. The mass of iron found from the working curve based on the measured absorbance of the blank test solution, mg; the mass of the sample, g.
6.7.7 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.0005%. 6.8 Determination of whiteness
6.8.1 Summary of method
Make a white plate with the sample using a sample press, compare it with a white plate made with a magnesium oxide whiteness standard sample, and measure the whiteness value on a whiteness meter. 6.8.2 Instruments and equipment
6.8.2.1 Whiteness meter: the same as specified in Chapter 3 of GB/T5950-86. 6.8.2.2 Standard white plate: the same as the magnesium oxide standard white plate specified in Chapter 4 of GB/T5950-86. 6.8.2.3 Working white plate: the same as specified in Chapter 5 of GB/T5950-86. 6.8.3 Analysis steps
Perform according to the provisions of Chapter 6 of GB/T5950-86. 6.8.4 Expression of analysis results
Perform according to the provisions of Chapter 7 of GB/T5950-86. 6.8.5 Allowable difference
The arithmetic mean of the parallel determination results shall be taken as the determination result. The absolute difference of the parallel determination results shall not exceed 1%. 6.9 Determination of oil absorption
6.9.1 Summary of the method
The amount of refined linseed oil absorbed by the sample under specified conditions. 6.9.2 Reagents and materials
· (2)
Same as Chapter 4 of GB/T5211.15-88.
6.9.3 Instruments and equipment
Same as Chapter 5 of GB/T5211.15-88.
6.9.4 Analysis steps
GB/T2899—1996
Weigh 10g of sample, accurate to 0.1g, and place on a flat plate. Add linseed oil from a dropper of known mass containing linseed oil, 4 to 5 drops at a time. Use a spatula to grind continuously after each addition of oil. Add drop by drop when near the end point. When the last drop is added, the sample is wetted by the oil and forms a whole ball. When it spreads without cracking or breaking, and can adhere to the flat plate, it is the end point. All operations should be completed within 20 to 25 minutes, and finally weigh the dropper.
6.9.5 Expression of analysis results
The oil absorption (X3) expressed as the mass of oil absorbed by every 100g of sample is calculated according to formula (3); m2×100
Where: ml——the mass of refined linseed oil consumed, g; the mass of the sample, g.
6.9.6 Allowable difference
The arithmetic mean of the parallel determination results shall be taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 1.0%. 6.10 Determination of pH value
According to GB/T1717-86, except that the 5-min standing time is changed to 10-min standing time. 6.11 Determination of fineness
6.11.1 Summary of method
Disperse the sample with water and pour it into the sieve. After repeating several times, rinse the sieve with water until the washing liquid is clear, dry the sieve and weigh it. 6.11.2 Instruments and equipment
6.11.2.1 Test sieve: meet the requirements of GB/T6003-85R40/3 series, p200mm×50mm/45μm. 6.11.2.2 Water supply: water pressure equal to 1m water column. 6.11.2.3 Sprinkler: prepared according to Figure 1.
6.11.2.4 Glass crucible: pore size 16~40μm. (3)
6.11.3 Analysis steps
GB/T 2899--1996
25 rows of equidistant holes, pore size 0.4~0.5mm
There are 25 holes in the center, and the holes in each row are arranged alternately. The center of the hole near the edge is not less than 1mm from the edge.
Sieve plate made of any suitable metal
Figure 1 Sprinkler for washing sieve residue
Weigh 200g of sample, accurate to 0.1g, placed in an 800mL beaker, first add an appropriate amount of water (usually 500-600mL), stir with a glass rod with a rubber head to help it disperse, pour the dispersed suspension into the sieve, rinse the residue on the sieve back into the beaker with water, and disperse it again with the same amount of water, pour it into the sieve as described above, and repeat this operation twice. Flush out all the residue in the beaker with water, use a sprinkler connected to a water supply device with a water pressure of 1m water level to rinse the residue on the sieve until the washing liquid is clear, wash the residue into a glass sand crucible with a constant weight in advance, and dry it in an oven at 105±2℃ to constant weight. 6.11.4 Expression of analytical results
The fineness (X,) expressed as a mass percentage is calculated according to formula (4): ml×100
Where: mi-
mass of the sieve residue, g;
mass of the sample, g.
6.11.5 Allowable difference
GB/T 2899--1996
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 0.03%. 6.12 Determination of particle size distribution
6.12.1 Summary of method
The falling rate of spherical particles through their dispersion medium is proportional to the square of the particle diameter. The particle distribution is expressed based on the distribution of spherical particles with the same sedimentation velocity. The determination is to prepare a dilute suspension, measure the solid concentration at a fixed point below the surface at a series of time intervals, and calculate its true spherical particle diameter. 6.12.2 Reagents and materials
Dispersant: sodium hexametaphosphate, 1g/L solution. 6.12.3 Instruments and equipment
6.12.3.1 Sedimentation pipette: as shown in Figure 2 (consisting of a sedimentator and a pipette). 10mI
Sampler
Inner diameter 1～1.3
Figure 2 Sedimentation pipette
Inner diameter 4～4.5
Air hole 3
Ground joint connection
Effective capacity height
(Graduation value 1mm)
Inner diameter 53~56
Inner diameter 1 ~~1. 3
GB/T 2899-—1996
6.12.3.2 Mechanical agitator: Generally 1000r/min, the agitator can be a 40mm diameter, thin stainless steel disc with four cuts and turned upward at an angle of 30°
6.12.3.3 Constant temperature water bath: The installation location should be far away from the vibration source, and the operating system should not cause vibration. 6.12.4 Sedimentation pipette calibration
Wash the sedimentation pipette, dry it naturally at room temperature, and weigh it to the nearest 0.1g. Then, inject water at room temperature to the 200mm mark, and weigh it again. Calculate the internal volume (V.) of the sedimentation vessel based on the mass of water. Then, use the upper pipette to transfer 10mL of water into a weighing bottle of known mass, weigh it to the nearest 0.001g, and calculate the internal volume (V,) of the pipette based on the mass of water. 6.12.5 Analysis steps
6.12.5.1 Sedimentation
Weigh 20g of the sample to the nearest 0.01g, place it in a 1000mL beaker, and add 500mL of sodium hexametaphosphate solution. Stir it with a stirrer for 15min, immediately pour all the suspension into the sedimentation vessel, and rinse the beaker with water to the 200mm mark. Transfer the sedimentation pipette to a constant temperature water bath and immerse the sedimentation device to the 200mm mark until it is in equilibrium with the water bath temperature (control the water bath temperature to be slightly higher than the room temperature, and can be selected from the following four levels: 23±0.5℃, 30±0.5℃, 35±0.5℃, 40±0.5℃). Then, plug the exhaust hole with your hand and turn the container upside down several times to mix the internal suspension evenly, immediately put it back to its original position and start timing. Calculate the sedimentation time of particles corresponding to 10μm, 5μm and 2μm diameters according to formula (5) for sampling. Each time, draw 10mL of suspension, and the full absorption time should be 20s. Drain the suspension from the pipette into a weighing bottle with constant weight, rinse the pipette with 5~~7mL of water, combine the washing liquid in the weighing bottle, and place it in an oven at 105±2℃ to dry until constant weight. Deduct the mass of the blank test to obtain the mass (mn) of the pure suspension drawn each time.
6.12.5.2 Calculation of sampling time:
18n·h.103
(pz - pi)gd
Wherein: t, —sampling time corresponding to the nth particle, s, (5)
viscosity of the dispersed solution, centipoise\(In this standard, the effect of sodium hexametaphosphate on viscosity can be ignored, and only the viscosity of pure water is considered. The viscosity of water is 723C = 0.936 centipoise, 730C - 0.801 centipoise, 735°C = 0.723 centipoise, 7400.656 centipoise);
-arithmetic mean depth from the lower end of the pipette to the suspension surface when taking the nth sample, mm; h.
P -density of the dispersed solution, g/cm2 (in this standard, the effect of sodium hexametaphosphate on the density can be ignored, and only the density of pure water is considered, the density of water p23c = 0.998 g/cm2, P30c = 0.996 g/cm2, 35c = 0.994 g/cm2, P40c = 0.992 g/cm2*);
P2--density of barium sulfate, g/cm2 (paso. = 4.5 g/cm2); g---gravitational acceleration, 9.81 m/s;
d--limiting diameter of the corresponding nth sample particle, μm (in this standard, di = 10 μm, dz = = 5 μm, d: = 2 μm). 6.12.6 Expression of analysis results
The diameter of the barium sulfate particles expressed in mass percentage is less than d. The content (Xs) is calculated according to formula (6): mV
Xs = 3
Wherein: mn——mass of pure suspension absorbed for the nth time, mass of sample, g
V. Corrected pipette volume, mL,
——corrected sedimentation container volume, mL. 1) 1 poise (P) = 100 centipoise (cP), 1P = 0.1 Pa*s234
· (6)
6.12.7 Allowable error
GB/T2899—1996
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 4.0%. 7 Marking, packaging, transportation, storage
7.1 The packaging of industrial precipitated barium sulfate should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, this standard number and mark 7 "wet-afraid" mark specified in GB191. 7.2 Industrial precipitated sulfuric acid should be tested by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer should ensure that each batch of products shipped meets the requirements of this standard. Each batch of products shipped should be accompanied by a quality certificate, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 7.3 Industrial precipitated barium sulfate is double-packed, the inner packaging is ethylene plastic film bag, the thickness is not less than 0.07mm, the inner bag packaging volume should be larger than the outer bag; the outer packaging is plastic woven bag or composite plastic woven bag, its performance and inspection method should comply with the provisions of GB/T8946--88 and GB/T8947-88. The net weight of each bag is 25 or 50kg. 7.4 The inner bag of the package is tied with vinyl rope or other ropes of equivalent quality, or sealed with other equivalent methods. The outer bag is folded at a distance of not less than 30mm from the edge of the bag, and the edge is sewn with vinyl thread or other thread of equivalent quality at a distance of not less than 15mm from the edge of the bag. The stitch length is 7-12mm, the stitches are neat and uniform, and there is no leakage or skipping. 7.5 Industrial precipitated barium sulfate should be protected from rain, moisture and exposure during transportation. 7.6 Industrial precipitated barium sulfate should be stored in a ventilated and dry warehouse. 2351 Method Summary
The rate of descent of a spherical particle through its dispersion medium is proportional to the square of the particle diameter. The particle distribution is expressed in terms of the distribution of spherical particles with the same settling velocity. The determination is to prepare a dilute suspension, measure the solid concentration at a fixed point below the surface at a series of time intervals, and calculate its true spherical particle diameter. 6.12.2 Reagents and Materials
Dispersant: Sodium hexametaphosphate, 1 g/L solution. 6.12.3 Apparatus and Equipment
6.12.3.1 Sedimentation pipette: as shown in Figure 2 (consisting of a sedimentator and a pipette). 10mI
Sampler
Inner diameter 1～1.3
Figure 2 Sedimentation pipette
Inner diameter 4～4.5
Air hole 3
Ground joint connection
Effective capacity height
(Graduation value 1mm)
Inner diameter 53~56
Inner diameter 1 ~~1. 3
GB/T 2899-—1996
6.12.3.2 Mechanical agitator: Generally 1000r/min, the agitator can be a 40mm diameter, thin stainless steel disc with four cuts and turned upward at an angle of 30°
6.12.3.3 Constant temperature water bath: The installation location should be far away from the vibration source, and the operating system should not cause vibration. 6.12.4 Sedimentation pipette calibration
Wash the sedimentation pipette, dry it naturally at room temperature, and weigh it to the nearest 0.1g. Then, inject water at room temperature to the 200mm mark, and weigh it again. Calculate the internal volume (V.) of the sedimentation vessel based on the mass of water. Then, use the upper pipette to transfer 10mL of water into a weighing bottle of known mass, weigh it to the nearest 0.001g, and calculate the internal volume (V,) of the pipette based on the mass of water. 6.12.5 Analysis steps
6.12.5.1 Sedimentation
Weigh 20g of the sample to the nearest 0.01g, place it in a 1000mL beaker, and add 500mL of sodium hexametaphosphate solution. Stir it with a stirrer for 15min, immediately pour all the suspension into the sedimentation vessel, and rinse the beaker with water to the 200mm mark. Transfer the sedimentation pipette to a constant temperature water bath and immerse the sedimentation device to the 200mm mark until it is in equilibrium with the water bath temperature (control the water bath temperature to be slightly higher than the room temperature, and can be selected from the following four levels: 23±0.5℃, 30±0.5℃, 35±0.5℃, 40±0.5℃). Then, plug the exhaust hole with your hand and turn the container upside down several times to mix the internal suspension evenly, immediately put it back to its original position and start timing. Calculate the sedimentation time of particles corresponding to 10μm, 5μm and 2μm diameters according to formula (5) for sampling. Each time, draw 10mL of suspension, and the full absorption time should be 20s. Drain the suspension from the pipette into a weighing bottle with constant weight, rinse the pipette with 5~~7mL of water, combine the washing liquid in the weighing bottle, and place it in an oven at 105±2℃ to dry until constant weight. Deduct the mass of the blank test to obtain the mass (mn) of the pure suspension drawn each time.
6.12.5.2 Calculation of sampling time:
18n·h.103
(pz - pi)gd
Wherein: t, —sampling time corresponding to the nth particle, s, (5)
viscosity of the dispersed solution, centipoise\(In this standard, the effect of sodium hexametaphosphate on viscosity can be ignored, and only the viscosity of pure water is considered. The viscosity of water is 723C = 0.936 centipoise, 730C - 0.801 centipoise, 735°C = 0.723 centipoise, 7400.656 centipoise);
-arithmetic mean depth from the lower end of the pipette to the suspension surface when taking the nth sample, mm; h.
P -density of the dispersed solution, g/cm2 (in this standard, the effect of sodium hexametaphosphate on the density can be ignored, and only the density of pure water is considered, the density of water p23c = 0.998 g/cm2, P30c = 0.996 g/cm2, 35c = 0.994 g/cm2, P40c = 0.992 g/cm2*);
P2--density of barium sulfate, g/cm2 (paso. = 4.5 g/cm2); g---gravitational acceleration, 9.81 m/s;
d--limiting diameter of the corresponding nth sample particle, μm (in this standard, di = 10 μm, dz = = 5 μm, d: = 2 μm). 6.12.6 Expression of analysis results
The diameter of the barium sulfate particles expressed in mass percentage is less than d. The content (Xs) is calculated according to formula (6): mV
Xs = 3
Wherein: mn——mass of pure suspension absorbed for the nth time, mass of sample, g
V. Corrected pipette volume, mL,
——corrected sedimentation container volume, mL. 1) 1 poise (P) = 100 centipoise (cP), 1P = 0.1 Pa*s234
· (6)
6.12.7 Allowable error
GB/T2899—1996
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 4.0%. 7 Marking, packaging, transportation, storage
7.1 The packaging of industrial precipitated barium sulfate should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, this standard number and mark 7 "wet-afraid" mark specified in GB191. 7.2 Industrial precipitated sulfuric acid should be tested by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer should ensure that each batch of products shipped meets the requirements of this standard. Each batch of products shipped should be accompanied by a quality certificate, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 7.3 Industrial precipitated barium sulfate is double-packed, the inner packaging is ethylene plastic film bag, the thickness is not less than 0.07mm, the inner bag packaging volume should be larger than the outer bag; the outer packaging is plastic woven bag or composite plastic woven bag, its performance and inspection method should comply with the provisions of GB/T8946--88 and GB/T8947-88. The net weight of each bag is 25 or 50kg. 7.4 The inner bag of the package is tied with vinyl rope or other ropes of equivalent quality, or sealed with other equivalent methods. The outer bag is folded at a distance of not less than 30mm from the edge of the bag, and the edge is sewn with vinyl thread or other thread of equivalent quality at a distance of not less than 15mm from the edge of the bag. The stitch length is 7-12mm, the stitches are neat and uniform, and there is no leakage or skipping. 7.5 Industrial precipitated barium sulfate should be protected from rain, moisture and exposure during transportation. 7.6 Industrial precipitated barium sulfate should be stored in a ventilated and dry warehouse. 2351 Method SummarybzxZ.net
The rate of descent of a spherical particle through its dispersion medium is proportional to the square of the particle diameter. The particle distribution is expressed in terms of the distribution of spherical particles with the same settling velocity. The determination is to prepare a dilute suspension, measure the solid concentration at a fixed point below the surface at a series of time intervals, and calculate its true spherical particle diameter. 6.12.2 Reagents and Materials
Dispersant: Sodium hexametaphosphate, 1 g/L solution. 6.12.3 Apparatus and Equipment
6.12.3.1 Sedimentation pipette: as shown in Figure 2 (consisting of a sedimentator and a pipette). 10mI
Sampler
Inner diameter 1～1.3
Figure 2 Sedimentation pipette
Inner diameter 4～4.5
Air hole 3
Ground joint connection
Effective capacity height
(Graduation value 1mm)
Inner diameter 53~56
Inner diameter 1 ~~1. 3
GB/T 2899-—1996
6.12.3.2 Mechanical agitator: Generally 1000r/min, the agitator can be a 40mm diameter, thin stainless steel disc with four cuts and turned upward at an angle of 30°
6.12.3.3 Constant temperature water bath: The installation location should be far away from the vibration source, and the operating system should not cause vibration. 6.12.4 Sedimentation pipette calibration
Wash the sedimentation pipette, dry it naturally at room temperature, and weigh it to the nearest 0.1g. Then, inject water at room temperature to the 200mm mark, and weigh it again. Calculate the internal volume (V.) of the sedimentation vessel based on the mass of water. Then, use the upper pipette to transfer 10mL of water into a weighing bottle of known mass, weigh it to the nearest 0.001g, and calculate the internal volume (V,) of the pipette based on the mass of water. 6.12.5 Analysis steps
6.12.5.1 Sedimentation
Weigh 20g of the sample to the nearest 0.01g, place it in a 1000mL beaker, and add 500mL of sodium hexametaphosphate solution. Stir it with a stirrer for 15min, immediately pour all the suspension into the sedimentation vessel, and rinse the beaker with water to the 200mm mark. Transfer the sedimentation pipette to a constant temperature water bath and immerse the sedimentation device to the 200mm mark until it is in equilibrium with the water bath temperature (control the water bath temperature to be slightly higher than the room temperature, and can be selected from the following four levels: 23±0.5℃, 30±0.5℃, 35±0.5℃, 40±0.5℃). Then, plug the exhaust hole with your hand and turn the container upside down several times to mix the internal suspension evenly, immediately put it back to its original position and start timing. Calculate the sedimentation time of particles corresponding to 10μm, 5μm and 2μm diameters according to formula (5) for sampling. Each time, draw 10mL of suspension, and the full absorption time should be 20s. Drain the suspension from the pipette into a weighing bottle with constant weight, rinse the pipette with 5~~7mL of water, combine the washing liquid in the weighing bottle, and place it in an oven at 105±2℃ to dry until constant weight. Deduct the mass of the blank test to obtain the mass (mn) of the pure suspension drawn each time.
6.12.5.2 Calculation of sampling time:
18n·h.103
(pz - pi)gd
Wherein: t, —sampling time corresponding to the nth particle, s, (5)
viscosity of the dispersed solution, centipoise\(In this standard, the effect of sodium hexametaphosphate on viscosity can be ignored, and only the viscosity of pure water is considered. The viscosity of water is 723C = 0.936 centipoise, 730C - 0.801 centipoise, 735°C = 0.723 centipoise, 7400.656 centipoise);
-arithmetic mean depth from the lower end of the pipette to the suspension surface when taking the nth sample, mm; h.
P -density of the dispersed solution, g/cm2 (in this standard, the effect of sodium hexametaphosphate on the density can be ignored, and only the density of pure water is considered, the density of water p23c = 0.998 g/cm2, P30c = 0.996 g/cm2, 35c = 0.994 g/cm2, P40c = 0.992 g/cm2*);
P2--density of barium sulfate, g/cm2 (paso. = 4.5 g/cm2); g---gravitational acceleration, 9.81 m/s;
d--limiting diameter of the corresponding nth sample particle, μm (in this standard, di = 10 μm, dz = = 5 μm, d: = 2 μm). 6.12.6 Expression of analysis results
The diameter of the barium sulfate particles expressed in mass percentage is less than d. The content (Xs) is calculated according to formula (6): mV
Xs = 3
Wherein: mn——mass of pure suspension absorbed for the nth time, mass of sample, g
V. Corrected pipette volume, mL,
——corrected sedimentation container volume, mL. 1) 1 poise (P) = 100 centipoise (cP), 1P = 0.1 Pa*s234
· (6)
6.12.7 Allowable error
GB/T2899—1996
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 4.0%. 7 Marking, packaging, transportation, storage
7.1 The packaging of industrial precipitated barium sulfate should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, this standard number and mark 7 "wet-afraid" mark specified in GB191. 7.2 Industrial precipitated sulfuric acid should be tested by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer should ensure that each batch of products shipped meets the requirements of this standard. Each batch of products shipped should be accompanied by a quality certificate, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 7.3 Industrial precipitated barium sulfate is double-packed, the inner packaging is ethylene plastic film bag, the thickness is not less than 0.07mm, the inner bag packaging volume should be larger than the outer bag; the outer packaging is plastic woven bag or composite plastic woven bag, its performance and inspection method should comply with the provisions of GB/T8946--88 and GB/T8947-88. The net weight of each bag is 25 or 50kg. 7.4 The inner bag of the package is tied with vinyl rope or other ropes of equivalent quality, or sealed with other equivalent methods. The outer bag is folded at a distance of not less than 30mm from the edge of the bag, and the edge is sewn with vinyl thread or other thread of equivalent quality at a distance of not less than 15mm from the edge of the bag. The stitch length is 7-12mm, the stitches are neat and uniform, and there is no leakage or skipping. 7.5 Industrial precipitated barium sulfate should be protected from rain, moisture and exposure during transportation. 7.6 Industrial precipitated barium sulfate should be stored in a ventilated and dry warehouse. 23501g, placed in a 1000mL beaker, add 500mL sodium hexametaphosphate solution. Stir with a stirrer for 15 minutes, immediately pour all the suspension into the settler, rinse the beaker with water to make the water volume reach the 200mm mark. Transfer the sedimentation pipette to a constant temperature water bath, immerse the settler to the 200mm mark, until it is balanced with the water bath temperature (control the water bath temperature slightly higher than room temperature, which can be selected from the following four levels: 23±0.5℃, 30±0.5℃, 35±0.5℃, 40±0.5℃). Then block the exhaust hole with your hand and turn the container upside down several times to mix the internal suspension evenly, immediately put it back to its original place and start timing. Calculate the sedimentation time of particles corresponding to 10μm, 5μm and 2μm diameters according to formula (5) for sampling, and absorb 10mL of suspension each time, and the full absorption time should be 20s. Drain the suspension from the pipette into a weighing bottle with constant weight, rinse the pipette with 5~7mL of water, combine the washing liquid in the weighing bottle, and place it in an oven at 105±2℃ to dry until constant weight. Subtract the mass of the blank test to obtain the mass (mn) of the pure suspension absorbed each time.
6.12.5.2 Calculation of sampling time:
18n·h.103
(pz - pi)gd
Wherein: t, —sampling time corresponding to the nth particle, s, (5)
viscosity of the dispersed solution, centipoise\(In this standard, the effect of sodium hexametaphosphate on viscosity can be ignored, and only the viscosity of pure water is considered. The viscosity of water is 723C = 0.936 centipoise, 730C - 0.801 centipoise, 735°C = 0.723 centipoise, 7400.656 centipoise);
-arithmetic mean depth from the lower end of the pipette to the suspension surface when taking the nth sample, mm; h.
P -density of the dispersed solution, g/cm2 (in this standard, the effect of sodium hexametaphosphate on the density can be ignored, and only the density of pure water is considered, the density of water p23c = 0.998 g/cm2, P30c = 0.996 g/cm2, 35c = 0.994 g/cm2, P40c = 0.992 g/cm2*);
P2--density of barium sulfate, g/cm2 (paso. = 4.5 g/cm2); g---gravitational acceleration, 9.81 m/s;
d--limiting diameter of the corresponding nth sample particle, μm (in this standard, di = 10 μm, dz = = 5 μm, d: = 2 μm). 6.12.6 Expression of analysis results
The diameter of the barium sulfate particles expressed in mass percentage is less than d. The content (Xs) is calculated according to formula (6): mV
Xs = 3
Wherein: mn——mass of pure suspension absorbed for the nth time, mass of sample, g
V. Corrected pipette volume, mL,
——corrected sedimentation container volume, mL. 1) 1 poise (P) = 100 centipoise (cP), 1P = 0.1 Pa*s234
· (6)
6.12.7 Allowable error
GB/T2899—1996
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 4.0%. 7 Marking, packaging, transportation, storage
7.1 The packaging of industrial precipitated barium sulfate should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, this standard number and mark 7 "wet-afraid" mark specified in GB191. 7.2 Industrial precipitated sulfuric acid should be tested by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer should ensure that each batch of products shipped meets the requirements of this standard. Each batch of products shipped should be accompanied by a quality certificate, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 7.3 Industrial precipitated barium sulfate is double-packed, the inner packaging is ethylene plastic film bag, the thickness is not less than 0.07mm, the inner bag packaging volume should be larger than the outer bag; the outer packaging is plastic woven bag or composite plastic woven bag, its performance and inspection method should comply with the provisions of GB/T8946--88 and GB/T8947-88. The net weight of each bag is 25 or 50kg. 7.4 The inner bag of the package is tied with vinyl rope or other ropes of equivalent quality, or sealed with other equivalent methods. The outer bag is folded at a distance of not less than 30mm from the edge of the bag, and the edge is sewn with vinyl thread or other thread of equivalent quality at a distance of not less than 15mm from the edge of the bag. The stitch length is 7-12mm, the stitches are neat and uniform, and there is no leakage or skipping. 7.5 Industrial precipitated barium sulfate should be protected from rain, moisture and exposure during transportation. 7.6 Industrial precipitated barium sulfate should be stored in a ventilated and dry warehouse. 23501g, placed in a 1000mL beaker, add 500mL sodium hexametaphosphate solution. Stir with a stirrer for 15 minutes, immediately pour all the suspension into the settler, rinse the beaker with water to make the water volume reach the 200mm mark. Transfer the sedimentation pipette to a constant temperature water bath, immerse the settler to the 200mm mark, until it is balanced with the water bath temperature (control the water bath temperature slightly higher than room temperature, which can be selected from the following four levels: 23±0.5℃, 30±0.5℃, 35±0.5℃, 40±0.5℃). Then block the exhaust hole with your hand and turn the container upside down several times to mix the internal suspension evenly, immediately put it back to its original place and start timing. Calculate the sedimentation time of particles corresponding to 10μm, 5μm and 2μm diameters according to formula (5) for sampling, and absorb 10mL of suspension each time, and the full absorption time should be 20s. Drain the suspension from the pipette into a weighing bottle with constant weight, rinse the pipette with 5~7mL of water, combine the washing liquid in the weighing bottle, and place it in an oven at 105±2℃ to dry until constant weight. Subtract the mass of the blank test to obtain the mass (mn) of the pure suspension absorbed each time.
6.12.5.2 Calculation of sampling time:
18n·h.103
(pz - pi)gd
Wherein: t, —sampling time corresponding to the nth particle, s, (5)
viscosity of the dispersed solution, centipoise\(In this standard, the effect of sodium hexametaphosphate on viscosity can be ignored, and only the viscosity of pure water is considered. The viscosity of water is 723C = 0.936 centipoise, 730C - 0.801 centipoise, 735°C = 0.723 centipoise, 7400.656 centipoise);
-arithmetic mean depth from the lower end of the pipette to the suspension surface when taking the nth sample, mm; h.
P -density of the dispersed solution, g/cm2 (in this standard, the effect of sodium hexametaphosphate on the density can be ignored, and only the density of pure water is considered, the density of water p23c = 0.998 g/cm2, P30c = 0.996 g/cm2, 35c = 0.994 g/cm2, P40c = 0.992 g/cm2*);
P2--density of barium sulfate, g/cm2 (paso. = 4.5 g/cm2); g---gravitational acceleration, 9.81 m/s;
d--limiting diameter of the corresponding nth sample particle, μm (in this standard, di = 10 μm, dz = = 5 μm, d: = 2 μm). 6.12.6 Expression of analysis results
The diameter of the barium sulfate particles expressed in mass percentage is less than d. The content (Xs) is calculated according to formula (6): mV
Xs = 3
Wherein: mn——mass of pure suspension absorbed for the nth time, mass of sample, g
V. Corrected pipette volume, mL,
——corrected sedimentation container volume, mL. 1) 1 poise (P) = 100 centipoise (cP), 1P = 0.1 Pa*s234
· (6)
6.12.7 Allowable error
GB/T2899—1996
The arithmetic mean of the parallel determination results is taken as the determination result, and the absolute difference of the parallel determination results shall not exceed 4.0%. 7 Marking, packaging, transportation, storage
7.1 The packaging of industrial precipitated barium sulfate should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, this standard number and mark 7 "wet-afraid" mark specified in GB191. 7.2 Industrial precipitated sulfuric acid should be tested by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer should ensure that each batch of products shipped meets the requirements of this standard. Each batch of products shipped should be accompanied by a quality certificate, including: manufacturer name, factory address, product name, trademark, category, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 7.3 Industrial precipitated barium sulfate is double-packed, the inner packaging is ethylene plastic film bag, the thickness is not less than 0.07mm, the inner bag packaging volume should be larger than the outer bag; the outer packaging is plastic woven bag or composite plastic woven bag, its performance and inspection method should comply with the provisions of GB/T8946--88 and GB/T8947-88. The net weight of each bag is 25 or 50kg. 7.4 The inner bag of the package is tied with vinyl rope or other ropes of equivalent quality, or sealed with other equivalent methods. The outer bag is folded at a distance of not less than 30mm from the edge of the bag, and the edge is sewn with vinyl thread or other thread of equivalent quality at a distance of not less than 15mm from the edge of the bag. The stitch length is 7-12mm, the stitches are neat and uniform, and there is no leakage or skipping. 7.5 Industrial precipitated barium sulfate should be protected from rain, moisture and exposure during transportation. 7.6 Industrial precipitated barium sulfate should be stored in a ventilated and dry warehouse. 2354 The inner bag of the package is tied with vinyl rope or other rope of equivalent quality, or sealed with other equivalent methods. The outer bag is folded at a distance of not less than 30mm from the bag edge, and the edge is sewed with vinyl thread or other thread of equivalent quality at a distance of not less than 15mm from the bag edge. The stitch length is 7-12mm, the stitches are neat and uniform, and there is no leakage or skipping. 7.5 Industrial precipitated barium sulfate should be kept away from rain, moisture and exposure during transportation. 7.6 Industrial precipitated barium sulfate should be stored in a ventilated and dry warehouse. 2354 The inner bag of the package is tied with vinyl rope or other rope of equivalent quality, or sealed with other equivalent methods. The outer bag is folded at a distance of not less than 30mm from the bag edge, and the edge is sewed with vinyl thread or other thread of equivalent quality at a distance of not less than 15mm from the bag edge. The stitch length is 7-12mm, the stitches are neat and uniform, and there is no leakage or skipping. 7.5 Industrial precipitated barium sulfate should be kept away from rain, moisture and exposure during transportation. 7.6 Industrial precipitated barium sulfate should be stored in a ventilated and dry warehouse. 235
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