HG/T 2956.4-2001 Determination of total iron content in boron and magnesium ores Potassium dichromate volumetric method HG/T2956.4-2001 Standard download decompression password: www.bzxz.net

1cs 73.080
Chinese Chemical Industry Standard
HG/T 2956.2~2956.82001
Analytical methods for ascharite ores2002-01-24 Issued
2002.0701 Implementation
National Economic and Trade Commission IssuedbzxZ.net
Record number: 10101—2002
HG/T 2956.4—2001
This standard is formulated by the standard of chemical industry HG/F2956.41982. The standard is called HG/T29.4—1. This standard is issued by the State Administration of Chemical Industry and the Chemical Industry Bureau. The policies and regulations of this standard may be proposed. This standard is issued by the Chemical Industry Bureau. The responsible drafting unit of this standard is Lianyungang Design and Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are: Director Heping and Zhang Xiaohui. This standard was first issued in 1966 as a standard of the Ministry of Chemical Industry or the Ministry of Industry and Information Technology. 1352-66 is required for the analysis method of magnesium ore; in 1982, it was issued as a national standard (G3447.4-824) for the analysis of the total iron content of magnesium ore; in 1997, it was revised as a national standard for the promotion of chemical industry (B3117.-H2), and was renumbered as HG/T2955.1982. 12
Chemical Industry Standard of the People's Republic of China
Determination of the total iron content in magnesium ore
Potassium chromate volumetric method
Ascharlteores
Leterminaliun of lolal iroc euntcat-Putassium diclhromale rol wmelric merlox1Fan Tian
This standard specifies the determination of total iron content by the volumetric method. This standard is applicable to the determination of total iron content in magnesium ore products. 2 Cited standards
HG/T 2956. 4—2001
Replacement HG/T2056,+—1683
The provisions contained in the following standards are referenced in the six standards to match the provisions of this standard. When this standard is published, the versions shown are valid. All standards are subject to revision. Parties using the standards of the past years should discuss the possibility of using the latest versions of the following standards: GB/6(11988 Chemical compositions for determination of total iron content (volumetric analysis) Preparation of standard for determination of total iron content GH/668—1992 Analytical test materials For laboratory water, see Standard Test Methods (reg 15 (36S2: 1957) 3 Method Summary
The sample is decomposed with hydrochloric acid, sodium thiocyanate-methyl orange is used as an indicator, ferric iron is reduced by ferrous oxide and trichloride, sodium monoammonium sulfonate is used as an indicator, and titrated with a standard titration solution of potassium hydroxide. 4 Reagents and solutions
The specifications of water used in this standard should comply with the third-grade water in H/T82. The listed reagents, unless otherwise specified, refer to analytically pure reagents. 4.1 Hydrochloric acid solution: + 1
4.2 Phosphoric acid: 5+95.
4.3 Thiocyanate mixed acid solution,
Add 150mL of sodium hydroxide buffer into 70ml of water, add 150mL of phosphoric acid after cooling, mix 4.4 Chloride and sawdust solution: 5ng/T
Add 5g of iodine chloride to 20mL of aldehyde, dilute with water to 10mL, store in a brown container, 4.5 Trifluoride solution
15% titanium dioxide solution 1tL and 1-4 Salt magnetic liquid 4hml. mud, stored in brown energy, the surface is evenly layered with fluffy paraffin, use about 1 year, no or turbidity will be lost, 4.6 Potassium tungstate standard titration liquid: c (1/6K.Cr.) = 0.3200m0l/L, weigh 0.9807g pre-stored: 20℃: T dry unit weight standard potassium tungstate GB: 259-1U80), need to be in a 250ml beaker, add water solution into 1ml bottle, dilute with water to scale, shake well. 4.7 Sodium tungstate indicator liquid.
Weigh 25g sodium phosphate and dissolve in 100mL phosphoric acid solution (4.2): approved by National Economic and Trade Commission on January 24, 2002 and implemented on July 1, 2002
4.8 Methyl orange indicator solution: 1g/L water
4.9 Diamine magnetic phase indicator solution: 5/L, HG/T 2956. 4—2001
Weigh 0.5E-1000mL water, add 1~2ml of water, shake, and add 5 test samples
The sample passes the 125m test value (GB/T6003.1), dry at 105-110℃ for more than 2h, and cool in a desiccator to room temperature. 6.1 Weigh 9.1-0.5g of the sample (accurate to 0.0002g) in a 250ml beaker, moisten with a small amount of water, add 30ml hydrochloric acid, add the solution on the surface, boil on a hot plate for 30min, and then add 6.2. Heat until the solution turns pale yellow, add 1 drop of sodium pyrophosphate as an indicator, 2 drops of sodium sulfoxide as an indicator, 3 drops of sodium sulfoxide as an indicator, add 10ml of sodium sulfoxide as an indicator, add 15ml of the mixed acid solution, and immediately titrate with potassium sulfate until the solution turns a stable blue color. 7 Expression of analytical results
Total deficiency (in F, center:) expressed as mass percentage (X>) Substitute formula (1) to calculate: VX0.97985×100
0. 079 83
3 Tolerance
The actual volume of potassium suberaldehyde standard solution.nl/L.! Volume of potassium suberaldehyde standard solution, mE: mass of sample R:
.....【
The mass of trioxide in grams equivalent to potassium suberaldehyde standard solution (/SK,Cr.)—.)l/I.
Take the arithmetic mean of the parallel analysis results as the final analysis result. The absolute value of the parallel analysis results of the same laboratory and the absolute value of the analysis results of different experimental states should not be greater than the allowable difference listed in Table 1. Table 1 Tolerance
Total amount of trioxide
Same--laboratory
Different laboratory
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