This standard specifies the determination of iron in high-purity quartz sand. This standard is applicable to the analysis of various grades of high-purity quartz sand. SJ 3228.5-1989 Determination of Iron in High-Purity Quartz Sand SJ3228.5-1989 Standard download decompression password: www.bzxz.net
This standard specifies the determination of iron in high-purity quartz sand. This standard is applicable to the analysis of various grades of high-purity quartz sand.

Standard of the Ministry of Machinery and Electronics Industry of the People's Republic of China Determination of Iron in High-Purity Quartz Sand
1 Subject Content and Scope of Application
1.1 Subject ContentwwW.bzxz.Net
This standard specifies the determination of iron in high-purity quartz sand for the electronics industry. 1.2 Scope of Application
This standard applies to the analysis of high-purity quartz sand of various grades. 2
Referenced Standards
SJ3228.289 General Rules for Analysis of High-Purity Quartz Sand. 8 Method Summary
SJ3228.5-89
Trivalent iron ions and thiocyanate ions form a red complex in nitric acid medium for colorimetric determination. 4 Reagents
4.1 Hydrofluoric acid: 40%,
4.2 Nitric acid: 1:1s
4.3 Hydrogen peroxide: 30%,
4.4 Ammonium thiocyanate solution: 20%,
4.5 Isoamyl alcohol,
4.6 Iron standard solution: 0.01mgm1-1.
Accurately weigh 0.8634g of ferric ammonium sulfate [NH, Fe (SO4) 2·12H, OJ in a beaker and dissolve it with water. If it is turbid, add 1:1 nitric acid until it is clear. Then transfer it to a 11 volumetric flask, dilute it to the scale with water, shake it well for use, and then dilute this solution to 10 times for colorimetry. 5 Analysis steps
Accurately weigh 1g of the sample dried at 110℃, place it in the lining of a high-pressure crucible, wet it with water, and add 6ml of hydrofluoric acid and 1ml of 1:1 nitric acid. Shake gently, cover the liner, and put it in a stainless steel sleeve. Tighten the lid and place it in a constant temperature drying oven at 145℃ to dissolve for 2h. After cooling to room temperature, open the lid, gently push out the liner, and place the loose mouth on a 120℃ hot plate to evaporate to dryness, and add 2ml of 1:1 nitric acid. Dissolve the residue, cool and transfer it to a 50ml colorimetric tube with a 25ml scale, add 5ml of 20% ammonium thiocyanate solution, dilute to 25ml scale, shake well, add 5ml of isoamyl alcohol, shake for 30s, let it stand and separate, and visually compare the extract. At the same time, use the same conditions to make a reagent blank, and use a micropipette to add iron standard solution to prepare a standard color scale and compare it with the sample. Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on March 20, 1989-03-25, implemented on March 25, 1989

8Calculation
Fe (%)=
SJ3228.5—89
Wherein, V-volume of the consumed iron standard solution. ml, C concentration of the iron standard solution. mg·m1-\, m-weight of the sample. g.
Additional remarks:
This standard was proposed by the Electronic Standardization Research Institute of the Ministry of Machinery and Electronics Industry. Drafted.
This standard was drafted by the 18th Research Institute of the Ministry of Machinery and Electronics Industry and the Electronic Standardization Research Institute of the Ministry of Machinery and Electronics Industry. The main drafters of this standard are Qin Guozhen and Liu Chenggou. 2—
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