GB/T 3286.2-1998 Chemical analysis methods for limestone and dolomite - Determination of silicon dioxide content
Some standard content:
GB/T3286.2-1998
This standard amends GB/T3286.3-1982 "Chemical analysis method for limestone and dolomite - determination of silicon dioxide by perchloric acid dehydration gravimetric method" and GB/T3286.4-1988 "Chemical analysis method for limestone and dolomite - determination of silicon dioxide by molybdenum blue photometric method". This revision merges the two original standards into one standard, which is described in two parts: the first part is silicon blue photometric method, and the second part is perchloric acid dehydration gravimetric method. This standard adopts the method for determination of silicon dioxide in JISM8850:1994 "Chemical analysis method for limestone" in a non-equivalent manner. "Scope" clarifies that this standard is also applicable to the determination of silicon dioxide in metallurgical lime. "Allowable difference" adds the laboratory allowable difference. The sample amount, flux amount, leaching acid amount, etc. are adjusted in the silicon molybdenum blue photometric method. The prepared test solution can be used for the determination of silicon dioxide, calcium oxide, magnesium oxide, aluminum oxide and iron oxide at the same time, making the analysis method more practical. The measurement range of the silicon molybdenum blue photometric method is extended from the original 0.05%~1.80% to 0.05%~4.00%.
The sample decomposition of the perchloric acid dehydration weight method has been changed from the original standard to the acid-soluble residue alkali melting recovery to the decomposition scheme of first high-temperature burning of the sample and then acid dissolution.
GB/T3286 "Chemical analysis methods for limestone and dolomite" includes the following nine substandards: GB/T3286.1 Determination of calcium oxide content and magnesium oxide content; GB/T3286.2 Determination of silicon difluoride content; GB/T3286.3
Determination of aluminum oxide content;
GB/T 3286.4
Determination of iron oxide content;
GB/T3286.5 Determination of manganese oxide content;
GB/T3286.6 Determination of phosphorus content;
GB/T 3286.7 Determination of sulfur content;
GB/T3286.8 Determination of loss on ignition,
GB/T3286.9 Determination of carbon dioxide content. This standard replaces GB/T3286.3-1982 and GB/T3286.4--1988 from the date of implementation. This standard was proposed by the former Ministry of Metallurgical Industry of the People's Republic of China. This standard is under the jurisdiction of the Information Standards Institute of the former Ministry of Metallurgical Industry. This standard was drafted by Wuhan Iron and Steel (Group) Corporation. The drafting units of this standard are: Wuhan Iron and Steel (Group) Corporation Technology Center, Shougang Special Steel Company. The main drafters of this standard are: Liu Jixian, Cao Hongyan, Qiu Huaiguang, Liu Wanhua, Xu Jianping, Chen Zibin. This standard was first issued in July 1982, and the silicon molybdenum blue photometry was revised in September 1988. 43
1 Scope
National Standard of the People's Republic of China
Methods for chemical analysis oflimestone and dolomite
The determination of silicondioxide content
This standard specifies the determination of silicondioxide content by the molybdenum-silicon blue photometric method and the perchloric acid dehydration gravimetric method. GB/T3286.2-—1998
Replaces GB/T3286.3—1982
GB/T 3286. 4-1988
This standard applies to the determination of silicondioxide content in limestone and dolomite, and also to the determination of silicondioxide in metallurgical lime. The first part is the molybdenum blue photometric method, the measurement range is: silicon dioxide content 0.05% ~ 4.00%; the second part is the pernitrogen acid dehydration weight method, the measurement range is: silicon dioxide content greater than 2.00%.
2 Reference standards
The provisions contained in the following standards are constituted as the provisions of this standard through the use of faces in this 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. GB/T 2007.21987 General rules for sampling and sample preparation of bulk mineral products Manual sample preparation method GB/T 3286.1--1998 Chemical analysis methods for limestone and dolomite Determination of calcium oxide and magnesium oxide content GB/T 3286.3-1998 Chemical analysis methods for limestone and dolomite Determination of aluminum oxide content GB/T 3286. 4~-1998
3 Chemical analysis methods for limestone and dolomite Determination of iron oxide content Part 1 Silicon molybdenum blue photometric method
3 Summary of method
The sample is melted with a sodium carbonate-boric acid mixed flux and leached with dilute hydrochloric acid. Take a portion of the test solution, in a hydrochloric acid medium of about 0.15 mol/L, ammonium molybdate and silicic acid form silicomolybdenum heteropoly acid, human oxalic acid-sulfuric acid mixed acid, eliminate the interference of phosphorus and arsenic, and use ammonium ferrous sulfate to reduce it to silicomolybdenum blue, and measure the absorbance at a wavelength of 680nm (or 810nm) on a spectrophotometer. 4 Reagents
4.1 Mixed flux: Grind two parts of anhydrous sodium carbonate and one part of boric acid and mix well. 4.2 Hydrochloric acid (1+5).
4.3 Hydrochloric acid (1+14).
4.4 Ammonium molybdate solution (60g/L), filter before use if necessary. 4.5 Oxalic acid-sulfuric acid mixed acid: Weigh 35g oxalic acid (H, C, O2H, O) and dissolve it in 1000mL sulfuric acid (1+8). Approved by the State Administration of Quality and Technical Supervision on December 7, 1998 44
Implementation on July 1, 1999
GB/T 3286. 2-1998
4.6 Ammonium ferrous sulfate solution (60 g/L): Weigh 6 g of ammonium ferrous sulfate (Fe(NH4)2(SO4)·6H2O) and dissolve it in a small amount of water, add 3~~5 drops of ethyl acetate (pl.84 g/mL), and dilute with water to 100 ml. 4.7 Anhydrous ethanol.
4.8 Silicon dioxide standard solution
4.8.1 Weigh 0.2500 g of high-purity silicon dioxide (not less than 99.99%) that has been calcined at 950~1000℃ for 30 min and cooled to room temperature in a platinum crucible, add 3 g of mixed flux (4.1), mix well, and then cover with 1 g of mixed flux (4.1). Cover with a platinum cover (leave a gap), place the platinum in a 950℃ high-temperature furnace to melt for 10 minutes, take it out, and cool it to room temperature. Place the platinum and platinum cover in a polytetrafluoroethylene beaker containing 100mL of hot water, and heat at low temperature to extract the melt until the solution is clear. Wash out the platinum plate and platinum cover with hot water and cool it to room temperature. Transfer the solution to a 500mL volumetric flask, dilute it to the mark with water, mix it well, and immediately transfer it to a plastic bottle for storage. 1.00mL of this solution contains 500μg of silicon dioxide. 4.8.2 Transfer 50.00mL of the silicon dioxide standard solution (4.8.1) to a 500mL volumetric flask, dilute it to the mark with water, mix it well, and immediately transfer it to a plastic bottle. 1.00mL of this solution contains 50.0μg of silicon dioxide. 4.8.3 Transfer 20.00ml of the silicon dioxide standard solution (4.8.1) to a 500mL volumetric flask, dilute it to the mark with water, mix it well, and immediately transfer it to a plastic bottle. 1.00mL of this solution contains 20.0μg of silicon dioxide. 5 Instruments
Only common laboratory instruments and equipment are used in the analysis. 6 Sample preparation
Prepare the sample according to GB/T2007.2.
6.1 The sample should be processed to a particle size of less than 0.125mm. 6.2 Before analysis, the limestone and dolomite samples should be dried at 105-110℃ for 2h and placed in a desiccator to cool to room temperature. 6.3 The preparation of metallurgical lime samples should be carried out quickly. After preparation, the samples should be immediately placed in a ground-mouth bottle or plastic bag, sealed, and stored in a desiccator. The samples should not be dried before analysis.
7 Analysis steps
7.1 Sample quantity
Weigh 0.50g of sample, accurate to 0.0001g. For metallurgical lime samples, the sample should be weighed quickly. 7.2 Blank test
Perform a blank test along with the sample.
7.3 Sample decomposition and preparation of stock solution
7.3.1 Place the sample (7.1) in a platinum crucible pre-filled with 3.0g of mixed flux (4.1), mix, and then cover with 1.0g of mixed flux (4.1). Place the platinum crucible in a high-temperature furnace with a furnace temperature below 300℃ and cover it with a platinum lid (leave a gap). Gradually increase the furnace temperature to 950~~1000℃, melt for 10min, take out, rotate the platinum crucible, and cool. 7.3.2 Rinse the outer wall of the platinum crucible with water, place the platinum and the platinum lid in a 300ml beaker, add 75mL of hydrochloric acid (4.2), heat at low temperature to leach the melt, and wash out the platinum crucible and platinum lid with water. Heat at low temperature until the test solution is clear, and cool to room temperature. Transfer the solution to a 250mL volumetric flask, dilute to the mark with water, and mix well. This solution is used as a stock solution for determining the amount of silicon dioxide, calcium oxide, magnesium oxide, aluminum oxide, and iron oxide. Note: GB/T3286.1 complexometric titration method for determination of calcium oxide and magnesium oxide, GB/T3286.2 molybdenum blue photometric method for determination of silicon dioxide, GB/T3286.3 Chrome azuro blue S photometric method for determination of lead oxide content, GB/T3286.4 o-phenanthroline photometric method for determination of iron oxide content. The stock solutions prepared for each analytical method are the same. If the contents of these chemical components in the sample are determined at the same time, only one stock solution of the sample can be prepared, and then the samples are divided and determined according to each analytical method. 7.4 Determination
7.4.1 According to the silicon dioxide content of the sample, divide the stock solution (7.3.2) into a 100mL volumetric flask according to Table 1, add 8mL of anhydrous ethanol (4.7), add the corresponding amount of hydrochloric acid (4.3) according to Table 1, and immediately dilute with water to 50mL and mix. 45
Contains silicon dihydride, %
0. 05~~0. 25
>0. 25 ~~1. 00
>1. 00~4. 00
GB/T3286.2—1998
Volume of aliquot, mL
Volume of hydrochloric acid, mL
7.4.2 Add 5 mL of ammonium sawate solution (4.4), mix well, and place at room temperature for 20 min. When the room temperature is below 15°C, place in a warm water bath at about 30°C for 15~20 min.
7.4.3 Add 20 mL of oxalic acid-sulfuric acid mixture (4.5), mix well, and place for 1~2 min. Immediately add 5 mL of ammonium ferrous sulfate solution (4.6), dilute to the mark with water, and mix.
7.4.4 Transfer part of the color developing solution into an appropriate absorbent medium, and measure the absorbance at a wavelength of 680 nm using the corresponding blank test solution as a reference. The corresponding amount of silicon dioxide can be obtained from the working curve. Note: For color developing solutions with low content of silicon diamine, the absorbance can be measured at a wavelength of 810 nm. 7.5 Drawing of working curve
Pipette 0, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00 mL of silicon dioxide standard solution (4.8.3) or 0, 1.00, 2.00, 4.00, 6.00, 8.00 mL of silicon dioxide standard solution (4.8.2) into a 100 mL volumetric flask pre-filled with 10 mL of hydrochloric acid (4.3), add 8 mL of anhydrous ethanol (4.7), dilute to 50 mL with water, and mix well. The following operations are carried out according to 7.4.2 to 7.4.4. The reagent blank is used as the reference to measure the absorbance. The working curve is drawn with the amount of silicon dioxide as the horizontal axis and the absorbance as the vertical axis. 8. Description of the analysis results
Calculate the mass percentage of silicon dioxide according to formula (1): m·V
SiO, (%) =
Volume of stock solution, mL;
Where. V—bzxZ.net
Vi—volume of the stock solution, mL,
mi——amount of silicon dioxide found from the working curve, g; m
9. Allowable difference
Sample amount.
The difference between the results of two independent analyses in the laboratory and the difference between the results of two laboratories should not be greater than the corresponding allowable difference listed in Table 2. For the sample of gold lime, no allowable difference requirement between laboratories is required. Table 2
Silicon dioxide content
0. 05 ~0. 20
>0.20~0.50
>0.50~1.00
>1. 00～~2. 00
>2. 00 ~ 4. 00
10Method Summary
Part II
Permissible difference within the laboratory
Perfluoric acid dehydration weight method
Permissible difference between laboratories
The sample is burned at high temperature, decomposed by hydrochloric acid, and dehydrated by adding perchloric acid evaporation tube smoke, filtered, burned and weighed. Impure silicon dioxide is treated with hydrofluoric acid and sulfuric acid to volatilize and remove silicon in the form of silicon tetrafluoride, and burned again. The silicon dioxide content is calculated from the mass difference before and after the hydrofluoric acid treatment. 46
11 Reagents
11.1 Hydrochloric acid (1+1).
11.2 Hydrochloric acid (5+95).
11.3 Perchloric acid (o1.67 g/mL).
11.4 Sulfuric acid (p 1. 84 g/ml.).
11.5 Hydrofluoric acid (p1.13 g/mL).
12 Instruments
GB/T3286.2—1998
In the analysis, only common laboratory instruments and equipment shall be used. 13 Sample preparation
Prepare the sample in accordance with GB/T2007.2.
13.1 The sample shall be processed to a particle size of less than 0.125 mm. 13.2 Before analysis, dry the limestone and dolomite samples at 105-110℃ for 2h and cool them in a desiccator to room temperature. 13.3 The preparation of metallurgical lime samples should be carried out quickly. After preparation, the samples are immediately placed in ground-mouth bottles or plastic bags and sealed, and stored in a desiccator. The samples are not dried before analysis.
14 Analysis steps
14.1 Sample quantity
Weigh 1.00g of sample to the nearest 0.0001g. For metallurgical lime samples, the sample should be weighed quickly. 14.2 Blank test
Carry out a blank test with the sample.
14.3 Determination
14.3.1 Place the sample (14.1) evenly in platinum. Place the platinum crucible in a high-temperature furnace with a furnace temperature below 300℃ and cover it with a platinum cover, leaving a gap between the platinum and the platinum cover. Gradually raise the furnace temperature to 1000℃ and keep it at this temperature for 30min. Take out the platinum and platinum and cool it down.
Note: The ignition residue after the determination of ignition loss can also be used as the test sample for this method. The following operations are carried out according to 14.3.2 to 14.3.7. 14.3.2 Use a small amount of water and hydrochloric acid (11.1) to transfer the ignition residue in the platinum crucible to a 300mL beaker, and wash the platinum and platinum cover. Cover with table III, slowly add 60mL hydrochloric acid (11.1), and heat the test solution to boiling. Cool slightly, rinse table III and the wall of the cup with water, and add 20mL perfluoric acid (11.3).
14.3.3 Cover with table blood (leave a gap), heat until white perchloric acid smoke comes out, and keep the smoke for 15min, and cool. 14.3.4 Add 5mL hydrochloric acid (11.1) and 100mL hot water, rinse Table III and the cup wall with a small amount of hot water, and stir to dissolve the salts. Filter with medium-speed quantitative filter paper and appropriate amount of pulp, wipe the precipitate on the cup wall with a glass rod with an eraser and a small piece of filter paper, and merge it onto the filter paper. Wash the beaker and precipitate six times with hot hydrochloric acid (11.2), and then wash the precipitate more than 10 times with hot water. 14.3.5 Add 10mL perchloric acid (11.3) to the filtrate and washing liquid, and repeat the operation of 14.3.3 to 14.3.4. 14.3.6 Place the precipitate and filter paper obtained twice in a platinum crucible, carefully dry and ash, and then place the platinum crucible in a high-temperature furnace at 1000℃ and burn for 30 minutes. Take it out, cool it slightly, place the platinum in a desiccator to cool to room temperature, weigh it, and repeat the burning until constant weight. 14.3.7 Wet the impure silica along the inner wall of the platinum crucible with a small amount of water, add three drops of sulfuric acid (11.4) and 5 mL of hydrofluoric acid (11.5), and heat to evaporate until all white smoke is emitted. Burn the platinum in a 1000℃ high-temperature furnace for 20 minutes. Take it out, cool it slightly, place the platinum tower in a desiccator to cool to room temperature, weigh it, and repeat the burning until the weight is constant. 47
15 Description of analysis results
GB/T3286.2—1998
Calculate the mass percentage of silicon dioxide according to formula (2): (m-mg)-(mama)
Si0,(%) =
Wherein: mi-
Mass of precipitate and platinum before hydrofluoric acid treatment, m; Mass of precipitate and platinum crucible after hydrofluoric acid treatment, g; Mass of blank test and platinum crucible before hydrofluoric acid treatment, g; Mass of blank test and platinum crucible after hydrofluoric acid treatment, g; mt-
Sample amount, g.
16 Allowable difference
The difference between two independent analysis results in a laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 3. For metallurgical lime samples, no allowable difference requirement between laboratories is required. Table 3
Silicon dioxide content
2.00 ~~4.00
Allowable difference within the laboratory
Allowable difference between laboratories00
>1. 00~4. 00
GB/T3286.2—1998
Taken volume, mL
Add hydrochloric acid volume, mL
7.4.2 Add 5 mL of ammonium saw acid solution (4.4), mix well, and place at room temperature for 20 min. When the room temperature is below 15°C, place in a warm water bath at about 30°C for 15~20 min.
7.4.3 Add 20 mL of oxalic acid-sulfuric acid mixture (4.5), mix well, and place for 1~2 min. Immediately add 5 mL of ammonium ferrous sulfate solution (4.6), dilute with water to the scale, and mix.
7.4.4 Transfer part of the color developing solution to an appropriate absorbent, use the corresponding blank test solution as a reference, measure the absorbance at a wavelength of 680 nm on a spectrophotometer, and obtain the corresponding amount of silicon dioxide from the working curve. Note: For the colorimetric solution with low content of silicon diamine, the absorbance can be measured at a wavelength of 810 nm. 7.5 Drawing of working curve
Pipette 0, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00 mL of silicon dioxide standard solution (4.8.3) or 0, 1.00, 2.00, 4.00, 6.00, 8.00 mL of silicon dioxide standard solution (4.8.2) into a 100 mL volumetric flask pre-filled with 10 mL of hydrochloric acid (4.3), add 8 mL of anhydrous ethanol (4.7), dilute to 50 mL with water, and mix well. The following operations are carried out according to 7.4.2 to 7.4.4, and the absorbance is measured with the reagent blank as the reference. Draw the working curve with the amount of silicon dioxide as the horizontal axis and the absorbance as the vertical axis. 8 Description of analysis results
Calculate the mass percentage of silicon dioxide according to formula (1): m·V
SiO, (%) =
Volume of stock solution, mL;
Wherein, V—
Vi—volume of the stock solution, mL,
mi——amount of silicon dioxide found from the working curve, g; m
9 Allowable difference
Sample amount.
The difference between two independent analysis results in the laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 2. For the sample of metallurgical lime, no allowable difference requirement between laboratories is required. Table 2
Silicon dioxide content
0. 05 ~0. 20
>0.20~0.50
>0.50~1.00
>1. 00～~2. 00
>2. 00 ~ 4. 00
10Method Summary
Part II
Permissible difference within the laboratory
Perfluoric acid dehydration weight method
Permissible difference between laboratories
The sample is burned at high temperature, decomposed by hydrochloric acid, and dehydrated by adding perchloric acid evaporation tube smoke, filtered, burned and weighed. Impure silicon dioxide is treated with hydrofluoric acid and sulfuric acid to volatilize and remove silicon in the form of silicon tetrafluoride, and burned again. The silicon dioxide content is calculated from the mass difference before and after the hydrofluoric acid treatment. 46
11 Reagents
11.1 Hydrochloric acid (1+1).
11.2 Hydrochloric acid (5+95).
11.3 Perchloric acid (o1.67 g/mL).
11.4 Sulfuric acid (p 1. 84 g/ml.).
11.5 Hydrofluoric acid (p1.13 g/mL).
12 Instruments
GB/T3286.2—1998
In the analysis, only common laboratory instruments and equipment shall be used. 13 Sample preparation
Prepare the sample in accordance with GB/T2007.2.
13.1 The sample shall be processed to a particle size of less than 0.125 mm. 13.2 Before analysis, dry the limestone and dolomite samples at 105-110℃ for 2h and cool them in a desiccator to room temperature. 13.3 The preparation of metallurgical lime samples should be carried out quickly. After preparation, the samples are immediately placed in ground-mouth bottles or plastic bags and sealed, and stored in a desiccator. The samples are not dried before analysis.
14 Analysis steps
14.1 Sample quantity
Weigh 1.00g of sample to the nearest 0.0001g. For metallurgical lime samples, the sample should be weighed quickly. 14.2 Blank test
Carry out a blank test with the sample.
14.3 Determination
14.3.1 Place the sample (14.1) evenly in platinum. Place the platinum crucible in a high-temperature furnace with a furnace temperature below 300℃ and cover it with a platinum cover, leaving a gap between the platinum and the platinum cover. Gradually raise the furnace temperature to 1000℃ and keep it at this temperature for 30min. Take out the platinum and platinum and cool it down.
Note: The ignition residue after the determination of ignition loss can also be used as the test sample for this method. The following operations are carried out according to 14.3.2 to 14.3.7. 14.3.2 Use a small amount of water and hydrochloric acid (11.1) to transfer the ignition residue in the platinum crucible to a 300mL beaker, and wash the platinum and platinum cover. Cover with table III, slowly add 60mL hydrochloric acid (11.1), and heat the test solution to boiling. Cool slightly, rinse table III and the wall of the cup with water, and add 20mL perfluoric acid (11.3).
14.3.3 Cover with table blood (leave a gap), heat until white perchloric acid smoke comes out, and keep the smoke for 15min, and cool. 14.3.4 Add 5mL hydrochloric acid (11.1) and 100mL hot water, rinse Table III and the cup wall with a small amount of hot water, and stir to dissolve the salts. Filter with medium-speed quantitative filter paper and appropriate amount of pulp, wipe the precipitate on the cup wall with a glass rod with an eraser and a small piece of filter paper, and merge it onto the filter paper. Wash the beaker and precipitate six times with hot hydrochloric acid (11.2), and then wash the precipitate more than 10 times with hot water. 14.3.5 Add 10mL perchloric acid (11.3) to the filtrate and washing liquid, and repeat the operation of 14.3.3 to 14.3.4. 14.3.6 Place the precipitate and filter paper obtained twice in a platinum crucible, carefully dry and ash, and then place the platinum crucible in a high-temperature furnace at 1000℃ and burn for 30 minutes. Take it out, cool it slightly, place the platinum in a desiccator to cool to room temperature, weigh it, and repeat the burning until constant weight. 14.3.7 Wet the impure silica along the inner wall of the platinum crucible with a small amount of water, add three drops of sulfuric acid (11.4) and 5 mL of hydrofluoric acid (11.5), and heat to evaporate until all white smoke is emitted. Burn the platinum in a 1000℃ high-temperature furnace for 20 minutes. Take it out, cool it slightly, place the platinum tower in a desiccator to cool to room temperature, weigh it, and repeat the burning until the weight is constant. 47
15 Description of analysis results
GB/T3286.2—1998
Calculate the mass percentage of silicon dioxide according to formula (2): (m-mg)-(mama)
Si0,(%) =
Wherein: mi-
Mass of precipitate and platinum before hydrofluoric acid treatment, m; Mass of precipitate and platinum crucible after hydrofluoric acid treatment, g; Mass of blank test and platinum crucible before hydrofluoric acid treatment, g; Mass of blank test and platinum crucible after hydrofluoric acid treatment, g; mt-
Sample amount, g.
16 Allowable difference
The difference between two independent analysis results in a laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 3. For metallurgical lime samples, no allowable difference requirement between laboratories is required. Table 3
Silicon dioxide content
2.00 ~~4.00
Allowable difference within the laboratory
Allowable difference between laboratories00
>1. 00~4. 00
GB/T3286.2—1998
Taken volume, mL
Add hydrochloric acid volume, mL
7.4.2 Add 5 mL of ammonium saw acid solution (4.4), mix well, and place at room temperature for 20 min. When the room temperature is below 15°C, place in a warm water bath at about 30°C for 15~20 min.
7.4.3 Add 20 mL of oxalic acid-sulfuric acid mixture (4.5), mix well, and place for 1~2 min. Immediately add 5 mL of ammonium ferrous sulfate solution (4.6), dilute with water to the scale, and mix.
7.4.4 Transfer part of the color developing solution to an appropriate absorbent, use the corresponding blank test solution as a reference, measure the absorbance at a wavelength of 680 nm on a spectrophotometer, and obtain the corresponding amount of silicon dioxide from the working curve. Note: For the colorimetric solution with low content of silicon diamine, the absorbance can be measured at a wavelength of 810 nm. 7.5 Drawing of working curve
Pipette 0, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00 mL of silicon dioxide standard solution (4.8.3) or 0, 1.00, 2.00, 4.00, 6.00, 8.00 mL of silicon dioxide standard solution (4.8.2) into a 100 mL volumetric flask pre-filled with 10 mL of hydrochloric acid (4.3), add 8 mL of anhydrous ethanol (4.7), dilute to 50 mL with water, and mix well. The following operations are carried out according to 7.4.2 to 7.4.4, and the absorbance is measured with the reagent blank as the reference. Draw the working curve with the amount of silicon dioxide as the horizontal axis and the absorbance as the vertical axis. 8 Description of analysis results
Calculate the mass percentage of silicon dioxide according to formula (1): m·V
SiO, (%) =
Volume of stock solution, mL;
Wherein, V—
Vi—volume of the stock solution, mL,
mi——amount of silicon dioxide found from the working curve, g; m
9 Allowable difference
Sample amount.
The difference between two independent analysis results in the laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 2. For the sample of metallurgical lime, no allowable difference requirement between laboratories is required. Table 2
Silicon dioxide content
0. 05 ~0. 20
>0.20~0.50
>0.50~1.00
>1. 00～~2. 00
>2. 00 ~ 4. 00
10Method Summary
Part II
Permissible difference within the laboratory
Perfluoric acid dehydration weight method
Permissible difference between laboratories
The sample is burned at high temperature, decomposed by hydrochloric acid, and dehydrated by adding perchloric acid evaporation tube smoke, filtered, burned and weighed. Impure silicon dioxide is treated with hydrofluoric acid and sulfuric acid to volatilize and remove silicon in the form of silicon tetrafluoride, and burned again. The silicon dioxide content is calculated from the mass difference before and after the hydrofluoric acid treatment. 46
11 Reagents
11.1 Hydrochloric acid (1+1).
11.2 Hydrochloric acid (5+95).
11.3 Perchloric acid (o1.67 g/mL).
11.4 Sulfuric acid (p 1. 84 g/ml.).
11.5 Hydrofluoric acid (p1.13 g/mL).
12 Instruments
GB/T3286.2—1998
In the analysis, only common laboratory instruments and equipment shall be used. 13 Sample preparation
Prepare the sample in accordance with GB/T2007.2.
13.1 The sample shall be processed to a particle size of less than 0.125 mm. 13.2 Before analysis, dry the limestone and dolomite samples at 105-110℃ for 2h and cool them in a desiccator to room temperature. 13.3 The preparation of metallurgical lime samples should be carried out quickly. After preparation, the samples are immediately placed in ground-mouth bottles or plastic bags and sealed, and stored in a desiccator. The samples are not dried before analysis.
14 Analysis steps
14.1 Sample quantity
Weigh 1.00g of sample to the nearest 0.0001g. For metallurgical lime samples, the sample should be weighed quickly. 14.2 Blank test
Carry out a blank test with the sample.
14.3 Determination
14.3.1 Place the sample (14.1) evenly in platinum. Place the platinum crucible in a high-temperature furnace with a furnace temperature below 300℃ and cover it with a platinum cover, leaving a gap between the platinum and the platinum cover. Gradually raise the furnace temperature to 1000℃ and keep it at this temperature for 30min. Take out the platinum and platinum and cool it down.
Note: The ignition residue after the determination of ignition loss can also be used as the test sample for this method. The following operations are carried out according to 14.3.2 to 14.3.7. 14.3.2 Use a small amount of water and hydrochloric acid (11.1) to transfer the ignition residue in the platinum crucible to a 300mL beaker, and wash the platinum and platinum cover. Cover with table III, slowly add 60mL hydrochloric acid (11.1), and heat the test solution to boiling. Cool slightly, rinse table III and the wall of the cup with water, and add 20mL perfluoric acid (11.3).
14.3.3 Cover with table blood (leave a gap), heat until white perchloric acid smoke comes out, and keep the smoke for 15min, and cool. 14.3.4 Add 5mL hydrochloric acid (11.1) and 100mL hot water, rinse Table III and the cup wall with a small amount of hot water, and stir to dissolve the salts. Filter with medium-speed quantitative filter paper and appropriate amount of pulp, wipe the precipitate on the cup wall with a glass rod with an eraser and a small piece of filter paper, and merge it onto the filter paper. Wash the beaker and precipitate six times with hot hydrochloric acid (11.2), and then wash the precipitate more than 10 times with hot water. 14.3.5 Add 10mL perchloric acid (11.3) to the filtrate and washing liquid, and repeat the operation of 14.3.3 to 14.3.4. 14.3.6 Place the precipitate and filter paper obtained twice in a platinum crucible, carefully dry and ash, and then place the platinum crucible in a high-temperature furnace at 1000℃ and burn for 30 minutes. Take it out, cool it slightly, place the platinum in a desiccator to cool to room temperature, weigh it, and repeat the burning until constant weight. 14.3.7 Wet the impure silica along the inner wall of the platinum crucible with a small amount of water, add three drops of sulfuric acid (11.4) and 5 mL of hydrofluoric acid (11.5), and heat to evaporate until all white smoke is emitted. Burn the platinum in a 1000℃ high-temperature furnace for 20 minutes. Take it out, cool it slightly, place the platinum tower in a desiccator to cool to room temperature, weigh it, and repeat the burning until the weight is constant. 47
15 Description of analysis results
GB/T3286.2—1998
Calculate the mass percentage of silicon dioxide according to formula (2): (m-mg)-(mama)
Si0,(%) =
Wherein: mi-
Mass of precipitate and platinum before hydrofluoric acid treatment, m; Mass of precipitate and platinum crucible after hydrofluoric acid treatment, g; Mass of blank test and platinum crucible before hydrofluoric acid treatment, g; Mass of blank test and platinum crucible after hydrofluoric acid treatment, g; mt-
Sample amount, g.
16 Allowable difference
The difference between two independent analysis results in a laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 3. For metallurgical lime samples, no allowable difference requirement between laboratories is required. Table 3
Silicon dioxide content
2.00 ~~4.00
Allowable difference within the laboratory
Allowable difference between laboratories4.4 Operation, take the reagent blank as reference, measure the absorbance. Draw the working curve with the amount of silicon dioxide as the horizontal axis and the absorbance as the vertical axis. 8 Description of the analysis results
Calculate the mass percentage of silicon dioxide according to formula (1): m·V
SiO, (%) =
Volume of stock solution, mL;
Where. V—
Vi—volume of the stock solution, mL,
mi——amount of silicon dioxide found from the working curve, g; m
9 Allowable difference
Sample amount.
The difference between two independent analysis results in the laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 2. For the sample of gold lime, no allowable difference requirement between laboratories is required. Table 2
Silicon dioxide content
0. 05 ~0. 20
>0.20~0.50
>0.50~1.00
>1. 00～~2. 00
>2. 00 ~ 4. 00
10Method Summary
Part II
Permissible difference within the laboratory
Perfluoric acid dehydration weight method
Permissible difference between laboratories
The sample is burned at high temperature, decomposed by hydrochloric acid, and dehydrated by adding perchloric acid evaporation tube smoke, filtered, burned and weighed. Impure silicon dioxide is treated with hydrofluoric acid and sulfuric acid to volatilize and remove silicon in the form of silicon tetrafluoride, and burned again. The silicon dioxide content is calculated from the mass difference before and after the hydrofluoric acid treatment. 46
11 Reagents
11.1 Hydrochloric acid (1+1).
11.2 Hydrochloric acid (5+95).
11.3 Perchloric acid (o1.67 g/mL).
11.4 Sulfuric acid (p 1. 84 g/ml.).
11.5 Hydrofluoric acid (p1.13 g/mL).
12 Instruments
GB/T3286.2—1998
In the analysis, only common laboratory instruments and equipment shall be used. 13 Sample preparation
Prepare the sample in accordance with GB/T2007.2.
13.1 The sample shall be processed to a particle size of less than 0.125 mm. 13.2 Before analysis, dry the limestone and dolomite samples at 105-110℃ for 2h and cool them in a desiccator to room temperature. 13.3 The preparation of metallurgical lime samples should be carried out quickly. After preparation, the samples are immediately placed in ground-mouth bottles or plastic bags and sealed, and stored in a desiccator. The samples are not dried before analysis.
14 Analysis steps
14.1 Sample quantity
Weigh 1.00g of sample to the nearest 0.0001g. For metallurgical lime samples, the sample should be weighed quickly. 14.2 Blank test
Carry out a blank test with the sample.
14.3 Determination
14.3.1 Place the sample (14.1) evenly in platinum. Place the platinum crucible in a high-temperature furnace with a furnace temperature below 300℃ and cover it with a platinum cover, leaving a gap between the platinum and the platinum cover. Gradually raise the furnace temperature to 1000℃ and keep it at this temperature for 30min. Take out the platinum and platinum and cool it down.
Note: The ignition residue after the determination of ignition loss can also be used as the test sample for this method. The following operations are carried out according to 14.3.2 to 14.3.7. 14.3.2 Use a small amount of water and hydrochloric acid (11.1) to transfer the ignition residue in the platinum crucible to a 300mL beaker, and wash the platinum and platinum cover. Cover with table III, slowly add 60mL hydrochloric acid (11.1), and heat the test solution to boiling. Cool slightly, rinse table III and the wall of the cup with water, and add 20mL perfluoric acid (11.3).
14.3.3 Cover with table blood (leave a gap), heat until white perchloric acid smoke comes out, and keep the smoke for 15min, and cool. 14.3.4 Add 5mL hydrochloric acid (11.1) and 100mL hot water, rinse Table III and the cup wall with a small amount of hot water, and stir to dissolve the salts. Filter with medium-speed quantitative filter paper and appropriate amount of pulp, wipe the precipitate on the cup wall with a glass rod with an eraser and a small piece of filter paper, and merge it onto the filter paper. Wash the beaker and precipitate six times with hot hydrochloric acid (11.2), and then wash the precipitate more than 10 times with hot water. 14.3.5 Add 10mL perchloric acid (11.3) to the filtrate and washing liquid, and repeat the operation of 14.3.3 to 14.3.4. 14.3.6 Place the precipitate and filter paper obtained twice in a platinum crucible, carefully dry and ash, and then place the platinum crucible in a high-temperature furnace at 1000℃ and burn for 30 minutes. Take it out, cool it slightly, place the platinum in a desiccator to cool to room temperature, weigh it, and repeat the burning until constant weight. 14.3.7 Wet the impure silica along the inner wall of the platinum crucible with a small amount of water, add three drops of sulfuric acid (11.4) and 5 mL of hydrofluoric acid (11.5), and heat to evaporate until all white smoke is emitted. Burn the platinum in a 1000℃ high-temperature furnace for 20 minutes. Take it out, cool it slightly, place the platinum tower in a desiccator to cool to room temperature, weigh it, and repeat the burning until the weight is constant. 47
15 Description of analysis results
GB/T3286.2—1998
Calculate the mass percentage of silicon dioxide according to formula (2): (m-mg)-(mama)
Si0,(%) =
Wherein: mi-
Mass of precipitate and platinum before hydrofluoric acid treatment, m; Mass of precipitate and platinum crucible after hydrofluoric acid treatment, g; Mass of blank test and platinum crucible before hydrofluoric acid treatment, g; Mass of blank test and platinum crucible after hydrofluoric acid treatment, g; mt-
Sample amount, g.
16 Allowable difference
The difference between two independent analysis results in a laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 3. For metallurgical lime samples, no allowable difference requirement between laboratories is required. Table 3
Silicon dioxide content
2.00 ~~4.00
Allowable difference within the laboratory
Allowable difference between laboratories4.4 Operation, take the reagent blank as reference, measure the absorbance. Draw the working curve with the amount of silicon dioxide as the horizontal axis and the absorbance as the vertical axis. 8 Description of the analysis results
Calculate the mass percentage of silicon dioxide according to formula (1): m·V
SiO, (%) =
Volume of stock solution, mL;
Where. V—
Vi—volume of the stock solution, mL,
mi——amount of silicon dioxide found from the working curve, g; m
9 Allowable difference
Sample amount.
The difference between two independent analysis results in the laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 2. For the sample of gold lime, no allowable difference requirement between laboratories is required. Table 2
Silicon dioxide content
0. 05 ~0. 20
>0.20~0.50
>0.50~1.00
>1. 00～~2. 00
>2. 00 ~ 4. 00
10Method Summary
Part II
Permissible difference within the laboratory
Perfluoric acid dehydration weight method
Permissible difference between laboratories
The sample is burned at high temperature, decomposed by hydrochloric acid, and dehydrated by adding perchloric acid evaporation tube smoke, filtered, burned and weighed. Impure silicon dioxide is treated with hydrofluoric acid and sulfuric acid to volatilize and remove silicon in the form of silicon tetrafluoride, and burned again. The silicon dioxide content is calculated from the mass difference before and after the hydrofluoric acid treatment. 46
11 Reagents
11.1 Hydrochloric acid (1+1).
11.2 Hydrochloric acid (5+95).
11.3 Perchloric acid (o1.67 g/mL).
11.4 Sulfuric acid (p 1. 84 g/ml.).
11.5 Hydrofluoric acid (p1.13 g/mL).
12 Instruments
GB/T3286.2—1998
In the analysis, only common laboratory instruments and equipment shall be used. 13 Sample preparation
Prepare the sample in accordance with GB/T2007.2.
13.1 The sample shall be processed to a particle size of less than 0.125 mm. 13.2 Before analysis, dry the limestone and dolomite samples at 105-110℃ for 2h and cool them in a desiccator to room temperature. 13.3 The preparation of metallurgical lime samples should be carried out quickly. After preparation, the samples are immediately placed in ground-mouth bottles or plastic bags and sealed, and stored in a desiccator. The samples are not dried before analysis.
14 Analysis steps
14.1 Sample quantity
Weigh 1.00g of sample to the nearest 0.0001g. For metallurgical lime samples, the sample should be weighed quickly. 14.2 Blank test
Carry out a blank test with the sample.
14.3 Determination
14.3.1 Place the sample (14.1) evenly in platinum. Place the platinum crucible in a high-temperature furnace with a furnace temperature below 300℃ and cover it with a platinum cover, leaving a gap between the platinum and the platinum cover. Gradually raise the furnace temperature to 1000℃ and keep it at this temperature for 30min. Take out the platinum and platinum and cool it down.
Note: The ignition residue after the determination of ignition loss can also be used as the test sample for this method. The following operations are carried out according to 14.3.2 to 14.3.7. 14.3.2 Use a small amount of water and hydrochloric acid (11.1) to transfer the ignition residue in the platinum crucible to a 300mL beaker, and wash the platinum and platinum cover. Cover with table III, slowly add 60mL hydrochloric acid (11.1), and heat the test solution to boiling. Cool slightly, rinse table III and the wall of the cup with water, and add 20mL perfluoric acid (11.3).
14.3.3 Cover with table blood (leave a gap), heat until white perchloric acid smoke comes out, and keep the smoke for 15min, and cool. 14.3.4 Add 5mL hydrochloric acid (11.1) and 100mL hot water, rinse Table III and the cup wall with a small amount of hot water, and stir to dissolve the salts. Filter with medium-speed quantitative filter paper and appropriate amount of pulp, wipe the precipitate on the cup wall with a glass rod with an eraser and a small piece of filter paper, and merge it onto the filter paper. Wash the beaker and precipitate six times with hot hydrochloric acid (11.2), and then wash the precipitate more than 10 times with hot water. 14.3.5 Add 10mL perchloric acid (11.3) to the filtrate and washing liquid, and repeat the operation of 14.3.3 to 14.3.4. 14.3.6 Place the precipitate and filter paper obtained twice in a platinum crucible, carefully dry and ash, and then place the platinum crucible in a high-temperature furnace at 1000℃ and burn for 30 minutes. Take it out, cool it slightly, place the platinum in a desiccator to cool to room temperature, weigh it, and repeat the burning until constant weight. 14.3.7 Wet the impure silica along the inner wall of the platinum crucible with a small amount of water, add three drops of sulfuric acid (11.4) and 5 mL of hydrofluoric acid (11.5), and heat to evaporate until all white smoke is emitted. Burn the platinum in a 1000℃ high-temperature furnace for 20 minutes. Take it out, cool it slightly, place the platinum tower in a desiccator to cool to room temperature, weigh it, and repeat the burning until the weight is constant. 47
15 Description of analysis results
GB/T3286.2—1998
Calculate the mass percentage of silicon dioxide according to formula (2): (m-mg)-(mama)
Si0,(%) =
Wherein: mi-
Mass of precipitate and platinum before hydrofluoric acid treatment, m; Mass of precipitate and platinum crucible after hydrofluoric acid treatment, g; Mass of blank test and platinum crucible before hydrofluoric acid treatment, g; Mass of blank test and platinum crucible after hydrofluoric acid treatment, g; mt-
Sample amount, g.
16 Allowable difference
The difference between two independent analysis results in a laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 3. For metallurgical lime samples, no allowable difference requirement between laboratories is required. Table 3
Silicon dioxide content
2.00 ~~4.00
Allowable difference within the laboratory
Allowable difference between laboratories1) Place the platinum crucible in a high-temperature furnace with a furnace temperature below 300°C and cover it with a platinum cover, leaving a gap between the platinum and the platinum cover. Gradually raise the furnace temperature to 1000°C and keep it at this temperature for 30 minutes. Take out the platinum and platinum and cool them down.
Note: The ignition residue after the determination of ignition loss can also be used as the test material for this method. The following operations are carried out according to 14.3.2 to 14.3.7. 14.3.2 Use a small amount of water and hydrochloric acid (11.1) to transfer the ignition residue in the platinum crucible to a 300mL beaker, and wash the platinum and platinum cover. Cover with Table III, slowly add 60mL of hydrochloric acid (11.1), and heat the test solution to boiling. Cool slightly, rinse Table III and the wall of the beaker with water, and add 20mL of perfluoric acid (11.3).
14.3.3 Cover the beaker with blood (leave a gap), heat until white perchloric acid smoke comes out, and keep the smoke for 15 minutes, then cool. 14.3.4 Add 5mL hydrochloric acid (11.1) and 100mL hot water, rinse the beaker III and the wall of the cup with a small amount of hot water, and stir to dissolve the salts. Filter with medium-speed quantitative filter paper and appropriate amount of pulp, wipe the precipitate on the wall of the cup with a glass rod with an eraser head and a small piece of filter paper, and merge it onto the filter paper. Wash the beaker and precipitate with hot hydrochloric acid (11.2) six times, and then wash the precipitate with hot water for more than 10 times. 14.3.5 Add 10mL perchloric acid (11.3) to the filtrate and washing liquid, and repeat the following steps 14.3.3 to 14.3.4. 14.3.6 Place the precipitate and filter paper obtained twice in a platinum crucible, carefully dry and ash, and then place the platinum crucible in a high-temperature furnace at 1000℃ and burn for 30 minutes. Take it out, cool it slightly, place the platinum in a desiccator to cool to room temperature, weigh it, and repeat the burning until the weight is constant. 14.3.7 Wet the impure silica along the inner wall of the platinum crucible with a small amount of water, add three drops of sulfuric acid (11.4) and 5mL of hydrofluoric acid (11.5), and heat to evaporate until all white smoke is emitted. Place the platinum in a high-temperature furnace at 1000℃ and burn it for 20 minutes. Take it out, cool it slightly, place the platinum tower in a desiccator to cool to room temperature, weigh it, and repeat the burning until the weight is constant. 47
15 Description of analysis results
GB/T3286.2—1998
Calculate the mass percentage of silicon dioxide according to formula (2): (m-mg)-(mama)
Si0,(%) =
Wherein: mi-
Mass of precipitate and platinum before hydrofluoric acid treatment, m; Mass of precipitate and platinum crucible after hydrofluoric acid treatment, g; Mass of blank test and platinum crucible before hydrofluoric acid treatment, g; Mass of blank test and platinum crucible after hydrofluoric acid treatment, g; mt-
Sample amount, g.
16 Allowable difference
The difference between two independent analysis results in a laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 3. For metallurgical lime samples, no allowable difference requirement between laboratories is required. Table 3
Silicon dioxide content
2.00 ~~4.00
Allowable difference within the laboratory
Allowable difference between laboratories1) Place the platinum crucible in a high-temperature furnace with a furnace temperature below 300°C and cover it with a platinum cover, leaving a gap between the platinum and the platinum cover. Gradually raise the furnace temperature to 1000°C and keep it at this temperature for 30 minutes. Take out the platinum and platinum and cool them down.
Note: The ignition residue after the determination of ignition loss can also be used as the test material for this method. The following operations are carried out according to 14.3.2 to 14.3.7. 14.3.2 Use a small amount of water and hydrochloric acid (11.1) to transfer the ignition residue in the platinum crucible to a 300mL beaker, and wash the platinum and platinum cover. Cover with Table III, slowly add 60mL of hydrochloric acid (11.1), and heat the test solution to boiling. Cool slightly, rinse Table III and the wall of the beaker with water, and add 20mL of perfluoric acid (11.3).
14.3.3 Cover the beaker with blood (leave a gap), heat until white perchloric acid smoke comes out, and keep the smoke for 15 minutes, then cool. 14.3.4 Add 5mL hydrochloric acid (11.1) and 100mL hot water, rinse the beaker III and the wall of the cup with a small amount of hot water, and stir to dissolve the salts. Filter with medium-speed quantitative filter paper and appropriate amount of pulp, wipe the precipitate on the wall of the cup with a glass rod with an eraser head and a small piece of filter paper, and merge it onto the filter paper. Wash the beaker and precipitate with hot hydrochloric acid (11.2) six times, and then wash the precipitate with hot water for more than 10 times. 14.3.5 Add 10mL perchloric acid (11.3) to the filtrate and washing liquid, and repeat the following steps 14.3.3 to 14.3.4. 14.3.6 Place the precipitate and filter paper obtained twice in a platinum crucible, carefully dry and ash, and then place the platinum crucible in a high-temperature furnace at 1000℃ and burn for 30 minutes. Take it out, cool it slightly, place the platinum in a desiccator to cool to room temperature, weigh it, and repeat the burning until the weight is constant. 14.3.7 Wet the impure silica along the inner wall of the platinum crucible with a small amount of water, add three drops of sulfuric acid (11.4) and 5mL of hydrofluoric acid (11.5), and heat to evaporate until all white smoke comes out. Place the platinum in a high-temperature furnace at 1000℃ and burn it for 20 minutes. Take it out, cool it slightly, place the platinum tower in a desiccator to cool to room temperature, weigh it, and repeat the burning until the weight is constant. 47
15 Description of analysis results
GB/T3286.2—1998
Calculate the mass percentage of silicon dioxide according to formula (2): (m-mg)-(mama)
Si0,(%) =
Wherein: mi-
Mass of precipitate and platinum before hydrofluoric acid treatment, m; Mass of precipitate and platinum crucible after hydrofluoric acid treatment, g; Mass of blank test and platinum crucible before hydrofluoric acid treatment, g; Mass of blank test and platinum crucible after hydrofluoric acid treatment, g; mt-
Sample amount, g.
16 Allowable difference
The difference between two independent analysis results in a laboratory and the difference between the analysis results of two laboratories should not be greater than the corresponding allowable difference listed in Table 3. For metallurgical lime samples, no allowable difference requirement between laboratories is required. Table 3
Silicon dioxide content
2.00 ~~4.00
Allowable difference within the laboratory
Allowable difference between laboratories
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