HG 2957.6-1984 Determination of combined water content of alum stone ore Gravimetric method HG2957.6-1984 standard download decompression password: www.bzxz.net

Scope of application
National Standard of the People's Republic of China
Determination of combined water content of alunite ore
Gravimetric method
Alunite ores-Determiation of combined water content --Gravimetrie method This standard specifies the determination of the combined water content in alunite ore by the gravimetric method of loss on ignition 2 Relevant standards
GB4581.1-84 "General rules for analysis of alunite ore". GB4581.2-84 "Methods for sampling and preparation of alunite ore analysis". Method summary
UDC:649.762
:543.21:546
The sample is ignited at 560°C for 3 hours, and the combined water content is calculated based on the weight loss. The alunite ore containing pyrite is treated with hydrogen peroxide solution in advance to remove the pyrite, and then ignited. 4 Apparatus and utensils
Muffle furnace: with automatic temperature controller.
Oven: with automatic temperature controller.
Porcelain: volume 10-15 ml.
4.4 Glass crucible: No. 4.
Reagents and solutions
5.1 Nitric acid (G 626-78) (specific gravity 1.42): 1 + 15.2 Nitric acid: 1 + 100
5.330% Hydrogen peroxide (HG3--1082-77): 15%. 6 Determination procedureswww.bzxz.net
6.1 Qualitative inspection
Take 1 gram of sample in a small beaker, add 10 ml of nitric acid solution (5.1), stir, cover with surface III, heat at low temperature, if brown gas escapes, determine the combined water according to 6.3; otherwise, determine according to 6.2. 6.2 Determination of combined water in samples without pyrite 6.2.1 Weigh 1 gram of sample into a constant weight porcelain crucible, place in a muffle furnace, heat from low temperature to 560℃, burn for 3 hours, take out and cool in a desiccator for 30 minutes, and weigh. 6.2.2 The white content (X) of combined water (H.O+) is calculated according to formula (1): National Bureau of Standards Issued on July 20, 1984
Implementation on June 1, 1985
Where: G
GB 4581,6-84
-weight of sample and porcelain crucible before burning, g;
-weight of sample and porcelain crucible after burning, g; W-weight of sample, g.
6.3 Determination of combined water in pyrite-containing samples (1)
6.3.1 Weigh 1 gram of sample into a 250 ml beaker 1, add 98 ml of hydrogen peroxide solution (5.3) and 2 ml of nitric acid solution (5.1): cover the surface, heat at low temperature (40-50°C), stir from time to time, remove when the effect is severe, and stir slightly. After the effect weakens, cool, filter with constant weight glass (4.4), first wash with nitric acid solution (5.2) 3 times: then wash the sample into the pit with water flow, and wash the beaker. Finally, wash the glass crucible with water 3 times (about 5 ml of water each time). Put the glass crucible in an oven at 120°C for 2 hours, take it out and cool it, weigh it, and then bake it to constant weight. Scrape the sample in the glass crucible gently with a spoon, and use a brush to brush off as much of the sample as possible. After weighing, place the sample in a constant weight porcelain furnace in a muffle furnace and heat from low temperature to 560℃ for 3 hours. Take it out and place it in a desiccator to cool for 30 minutes and weigh it. 6.3.2 Expression and calculation of results
The white content (Xs) of combined water (H2O) is calculated according to formula (2): W
(G1-G2) ×
W: G
Weight of sample and porcelain crucible before calcination, g; Weight of sample and porcelain crucible after calcination, g: "-Weight of sample in glass crucible after treatment with hydrogen peroxide solution, g; W2
Weight of sample in glass crucible, g! Weight of original sample, g.
Tolerance
Combined water content, %
Tolerance (absolute error), %
Additional remarks:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and the Institute of Chemical Industry and Mining of the Ministry of Chemical Industry. This standard was drafted by the Institute of Chemical Industry and Mining of the Ministry of Chemical Industry. The main drafter of this standard is Cheng Maomei.
From the date of implementation of this standard, the former Ministry of Chemical Industry Standard HG1-353-66 "Non-uniform analysis method of alum" shall be invalid. 2)
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