GB/T 3884.8-2000 Chemical analysis methods for copper concentrates - Determination of zinc content

This standard specifies the determination method of zinc content in copper concentrate. This standard is applicable to the determination of zinc content in copper concentrate. GB/T 3884.8-2000 Chemical analysis method for copper concentrate Determination of zinc content GB/T3884.8-2000 Standard download decompression password: www.bzxz.net

GB/T3884.8—2000
This standard is a reaffirmation of GB/T3884.13—1983 “Chemical analysis method for copper concentrate - EDTA volumetric method for determination of zinc content”, with only the determination range adjusted from 2.00%-12.00% to >1.00%~13.00%. This standard complies with:
GB/T 1.1—1993
Guidelines for standardization
Basic provisions
Unit 1: Rules for drafting and expressing standards Part 1: Rules for writing standards
GB/T1.41988
Guidelines for standardization
Rules for writing chemical analysis methods standards
3 General principles and general provisions for chemical analysis methods for metallurgical products GB/T1467--1978
GB/T17433—1998 Basic terms for chemical analysis of metallurgical products This standard replaces GB/T3884.13—1983 from the date of implementation. This standard is proposed by the State Bureau of Nonferrous Metals Industry. This standard is under the jurisdiction of the China Nonferrous Metals Industry Standard Metrology and Quality Research Institute. This standard is drafted by Daye Nonferrous Metals Company. This standard is drafted by Tongling Nonferrous Metals (Group) Company. The main drafters of this standard are Chen Xiaoyan, Shao Conghe and Feng Deyin. 41
1 Scope
National Standard of the People's Republic of China
Chemical analysis method of copper concentrate
Determination of zinc content
Methods for chemical analysis of copper concentrate-Determination of zinc contentThis standard specifies the determination method of zinc content in copper concentrate. This standard is applicable to the determination of zinc content in copper concentrate. Determination range:>1.00%～13.00%. 2 Principle of the method
GB/T3884.8—2000
Replaces GB/T3884.13—1983
After the sample is decomposed with acid, the interfering elements such as iron and manganese are separated in an ammonia buffer solution in the presence of an oxidant, and a masking agent is added to eliminate the interference of copper and aluminum. At pH 5.0～6.0, dimethyl phenol is used as an indicator and titrated with Na2EDTA standard titration solution. The result is the total amount of zinc and manganese, and the amount deducted is the amount of zinc.
3 Reagents
3.1 Ammonium chloride.
3.2 Potassium fluoride.
3.3 Ascorbic acid.
3.4 ​​Ammonia water (p0.90g/mL).
3.5 Hydrochloric acid (p1.19g/mL).
Homic acid (pl.67g/mL).
Hydrochloric acid (1+1).
Sulfuric acid (1+1).
Nitric and sulfuric acid: Mix 7 parts of nitric acid (pl.42g/mL) with 3 parts of sulfuric acid (p1.84g/mL). Ammonium persulfate solution (100g/L). Prepare before use. Saturated thiourea solution.
Buffer solution (pH 5.5): Dissolve 150g of anhydrous sodium acetate in water, add 50mL of acetic acid, dilute to 1000mL with water, and mix 3.13 Xylenol orange indicator (5g/L).
3.14 Washing solution: Dissolve 5g of ammonium nitride (3.1) in 200mL of nitrogen water (5+95). 3.15 Zinc standard solution: Weigh 1.0000g of metallic zinc (99.99%), place in a 300mL beaker, add 30mL of hydrochloric acid (3.7), place on a hot plate and heat to dissolve, cool, transfer to a 1000mL volumetric flask, dilute to scale with water, and mix well. This solution contains 1mg of zinc in 1mL. 3.16 Disodium ethylenediammonium tetraacetate (Na_EDTA) standard titration solution (0.01 mol/L) 3.16.1 Preparation
Weigh 3.7 g NaEDTA (CHNONaz·2HO) into a 500 mL beaker, add hot water to dissolve, cool, transfer to a 1000 mL volumetric flask, dilute to the mark with water, and mix well. 3.16.2 Calibration
Take three portions of 25.00 mL of zinc standard solution (3.15) and place them in 300 mL beakers respectively. Dilute to 50 mL with water and add 2-3 drops of xylenol orange indicator (3.13). Neutralize with ammonia water (3.4) until the solution turns slightly red. Add 20 mL of buffer solution (3.12) and titrate with NazEDTA standard titration solution (3.16) until the solution changes from slightly red to bright yellow. This is the end point. Calculate the actual concentration of the Na2EDTA standard titration solution according to formula (1): Co.V
Wherein: c-actual concentration of Na2EDTA standard titration solution, mol/L; Co
concentration of zinc standard solution, mg/mL;
M-molar mass of zinc, g/mol
Vvolume of zinc standard solution transferred, mL;
V2-volume of Na2EDTA standard titration solution consumed in titrating zinc standard solution, mL. .(1)
Take the average of the three calibration results. The extreme value of the three calibration results should not be greater than 3×10-5mol/L. Otherwise, recalibrate. 4 Sample
4.1 The sample particle size should not be greater than 0.082mm. 4.2 The sample should be dried at 100105℃ for 1h and then placed in a desiccator to cool to room temperature. 5 Analysis steps
5.1 Test material
Weigh 0.25g of test material, accurate to 0.0001g. Perform two independent determinations and take the average value. 5.2 Blank test
Perform a blank test with the test material.
5.3 Determination
5.3.1 Place the test material (5.1) in a 300mL beaker, moisten it with a small amount of water, add 10mL of hydrochloric acid (3.5), cover it with a watch glass, place it on a hot plate and heat for several minutes, remove it and cool it slightly. Add 10mL of nitric acid and sulfuric acid mixture, heat and evaporate until almost dry, and cool it slightly (if the test material has a high carbon content, when it is evaporated to white smoke, remove it and cool it slightly, add 2-3mL of perchloric acid, continue to evaporate until it is almost dry, and cool it slightly). 5.3.2 Add 4-5 drops of sulfuric acid and 50mL of water, boil to dissolve the soluble salts, and cool it slightly. Add 10g of ammonium chloride, neutralize with nitrogen water until hydroxide precipitation appears, and add 25mL in excess, add 5mL of ammonium persulfate solution, dilute with water to about 100mL, boil to destroy excess ammonium persulfate. Cool slightly, transfer to a 250mL volumetric flask, wash the beaker with hot detergent 4~5 times, dilute with water to the scale after cooling, and mix well. 5.3.3 Dry filter with medium-speed filter paper, take 100mL of filtrate, add 0.5g of potassium fluoride and 0.1g of ascorbic acid, stir to completely dissolve, add 3~4 drops of xylenol orange indicator, neutralize with sulfuric acid until the solution changes from light red to yellow, and then neutralize with ammonia water until the solution changes from yellow to red. Add 10mL of saturated sulfuric acid solution and 20mL of buffer solution, and titrate with Na,EDTA standard titration solution until the solution changes from light red to bright yellow, which is the end point. 6 Expression of analysis resultswww.bzxz.net
Calculate the percentage of zinc according to formula (2):
Zn(%) = .V(=V)X 0. 065 38 × 100 - Ca% × 0. 581 6m,.Vs
The actual concentration of Na-EDTA standard titration solution, mol/L; where ·c
V. -The volume of NaEDTA standard titration solution consumed in titrating the blank test solution during determination, mL; ·(2)
GB/T3884.8-2000
V,The volume of Na-EDTA standard titration solution consumed in titrating the sample solution during determination, mL, V.The dilution volume of the test solution, mL
V,The volume of the test solution taken, mL
m. —Mass of the sample.g
Cd%—Percentage measured by GB/T3884.6; —Mass of zinc equivalent to 1.00mL NazEDTA standard titration solution [c (NazEDTA) = 1.00mol/L], 0.06538-
g/mol;
Coefficient of converting the amount of zinc into the amount of zinc
The result is expressed to two decimal places.
7 Allowable difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 1. Table 1
Zinc content
>1.00~2.00
>2.00~3.00
>3.00~5.00
>5.00~8.00
>8. 00~13. 00
Allowable difference
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